Un padre para estimular a su hijo para estudiar matemáticas le dice: por cada ejercicio que resuelvas bien te daré 7 € y por cada uno que hagas mal me darás 1 €. Después de hacer 45 ejercicios, el muchacho se encuentra con 19 €. ¿Cuántos ejercicios ha resuelto bien?
Answer:
8 ejercicios
Step-by-step explanation:
De acuerdo a la información dada, puedes plantear las siguientes ecuaciones:
x+y= 45 (1)
7x-1y= 19 (2)
x= ejercicios que resolvió bien
y= ejercicios que resolvió mal
Primero, puedes despejar x en (1):
x= 45-y (3)
Segundo, debes reemplazar (3) en (2):
7(45-y)-1y=19
315-7y-1y= 19
315-8y= 19
315-19= 8y
296= 8y
y= 296/8
y= 37
Tercero, debes reemplazar el valor de y en (3) para encontrar x:
x= 45-37
x= 8
De acuerdo a esto, la respuesta es que el hijo ha resuelto bien 8 ejercicios.
Express 7040 in its standard form
Answer:
[tex]7.040 \times {10}^{3} [/tex]
Step-by-step explanation:
First write this number like this
[tex]7.040[/tex]
Then,
[tex]7.040 \times {10}^{3} [/tex]
To check whether your answer is correct you can do like this
[tex]7.040 \times {10}^{3} [/tex]
[tex] {10}^{3} = 10 \times 10 \times 10 \\ \: \: \: \: \: \: \: \: \: \: = 1000[/tex]
[tex]7.040 \times 1000 \\ = 7040[/tex]
yes, your answer is correct.
hope this helps
brainliest appreciated
good luck! have a nice day!
Decide whether the equation is a function, not a function, linear but not a function, or a linear function. Choose the best option.
8x-3y=-2
а
b
Function
Not a Function
Linear But Not a Linear Function
Linear Function
С
d
Answer:
Linear Function
Step-by-step explanation:
8x-3y = -2
-3y = 8x-2
3y = -8x+2
y = [tex]\frac{-8x+2}{3}[/tex]
y = [tex]-\frac{8}{3}x+\frac{2}{3}[/tex]
Linear Function
If anybody knows anything I beg you help PLS HELP
Answer:
7.809 g/cm^3
Step-by-step explanation:
Density is mass over volume so we need to find the mass and volume of the steel.
First we find the volume of the wood:
Vw = 9*6*6 = 324 cm^3
now we can find the mass of the wood, as mass = density * volume
mw = .68*324 = 220.32g
subtracting the mass of wood from total mass, we get the mass of steel
970-220.32 = 749.68g
now we can find the volume of the pyramid
Vs = 1/3 *6*6* (17-9) = 96 cm^3
Now we divide mass by volume to get density
749.68/96 = 7.809 g/cm^3
Confirming this with known data, density of steel is roughly between 7.75 and 8.05 g/cm^3 so we know we're correct.
In the diagram of circle O, what is the measure of ? 27° 54° 108° 120°
Answer:
Option (2).
Step-by-step explanation:
This question is incomplete; here is the complete question and find the figure attached.
In the diagram of a circle O, what is the measure of ∠ABC?
27°
54°
108°
120°
m(minor arc [tex]\widehat {AC}[/tex]) = 126°
m(major arc [tex]\widehat {AC}[/tex]) = 234°
By the intersecting tangents theorem,
If the two tangents of a circle intersect each other outside the circle, measure of angle formed between them is half the difference of the measures of the intercepted arcs.
m∠ABC = [tex]\frac{1}{2}[m(\text {major arc{AC})}-m(\text{minor arc} {AC})][/tex]
= [tex]\frac{1}{2}(234-126)[/tex]
= 54°
Therefore, Option (2) will be the answer.
Answer:
B.
Step-by-step explanation:
The area of a triangle garden can
be no more than 120 square
feet. The base of a triangle
is 16 feet in
lenght What
inequalitie describes the
possible heights, h, of the
triangular garden?
Answer:
0< h ≤ 15
Step-by-step explanation:
A = 1/2 * base * height = 1/2*16*h = 8h
A no more is ≤.
A ≤ 120
8h ≤ 120
h ≤ 15
0< h ≤ 15
Height should be more than 0 feet and no more than 15 feet.
Can someone help me with these
Answer:
Problem 2) : the gradient is "-2", and the y-intercept is "3"
Problem 3)
A is [tex]y=2x+2[/tex]
B is [tex]y=x+2[/tex]
Step-by-step explanation:
Problem 2)
In the line given by the equation: [tex]y=-2x+3[/tex]
the "gradient" (also known as "slope") is the numerical coefficient that multiplies the variable "x". So in this case the gradient is "-2"
the y-intercept is the numerical term "+3" because that is the y-value result of evaluating the expression for x = 0
[tex]y=-2x+3\\y=-2\,(0)+3\\y=3[/tex]
Problem 3)
Consider the two lines :
[tex]y=x+2[/tex] and [tex]y=2x+2[/tex]
notice that both have the same y-intercept (that is the numerical term "2" at the end of both expressions. That means that both lines cross the y-axis at the point y=2.
Now notice that the gradient of one of them is "1" (for [tex]y=x+2[/tex] ) that is the coefficient that multiplies the variable "x". While for the other line ( [tex]y=2x+2[/tex]) the gradient is "2" and therefore steeper than the previous one.
Then, the line identified as "A" which is the one with steeper gradient, corresponds to the equation [tex]y=2x+2[/tex], and the line identified with "B" is the one with smaller gradient [tex]y=x+2[/tex] .
HELP ASAP!! What is the output value for the following function, f(x) = 5x - 2 if the input value is 3?
A. 17
B.51
C. 13
D. 1
Please helpp!
Answer:
C) 13
Step-by-step explanation:
f(x) = 5x -2
f(3) = 5(3) -2
f(3) = 15 - 2
f(3l) = 13
Use the figure below. Which angle is congruent to ∠ACB? A. ∠ABC B. ∠AED C. ∠ADE D. ∠DAE
<AED
Explanation:
B is the mid point of AD.( since AB=BD)
C is the mid point of AB( since AC=BC)
Therefore BC is parallel to DE.
Angle ACB= Angle AEB
Corresponding angles are equal.
And hence, they are congruent.
Hope it helps
Good luck on your assignment
The angle congruent to ∠ACB is B. ∠AED.
What are congruent angles?Congruent angles are the angles that have equal measure. So all the angles that have equal measure will be called congruent angles.
Congruent Angles have the same angle (in degrees or radians).
Now from the given figure,
In triangle ABC and triangle AED
AC = CB
BC is parallel to DE
Thus, by law of congruent angles, interior angles are equal,
Thus, ∠ACB = ∠AED
this is the required congruent angle of ∠ACB.
Thus, the angle congruent to ∠ACB is B. ∠AED.
To learn more about congruent angles:
https://brainly.com/question/24887947
#SPJ2
Your history teachers is going to give you a 92 point assessment. There are 2 point questions and 3 point questions. If there is a total of 40 questions on the assessment, how many questions are worth 2 points?
Answer:
28
Step-by-step explanation:
x = 2 point questions, y = 3 point questions
x + y = 40
2x + 3y = 92
Solving this we get x = 28, y = 12 so the answer is 28.
Answer: 28
Step-by-step explanation:
Let x be the number of 2 mark questions
Let y be the number of 3 mark questions
x+y=40. ---------------(1)
2x+3y=92 ---------------(2)
Solve equation (1) for y
y=40−x
Substitute
y=40−x in equation (2)
2x+3(40−x)=92
2x+120−3x=92
2x−3x=92−120
−x=−28
x=28
Substitute
x=28 in equation (1)
28+y=40
y=40−28=12
Number of 2 mark questions
=28
Number of 3 mark questions
=12
Easy Grade 7 Math
First answer will be marked brainliest (has to have explanation)
Find the value of X! Thanks so much for your help :) Picture above
Answer:
Step-by-step explanation:
Angles x and z are supplementary, meaning that they add up to 180. From the markings on the diagram, angle z and the angle measuring 20 are complementary, meaning they add up to 90. So the game plan is to find out the measure of angle z first, then use that to find the measure of angle x.
angle z = 90 - 20 so
angle z = 70 degrees. And
angle z + angle x = 180. Subbing in our value for z:
70 + angle x = 180 and
angle x = 180 - 70 so
angle x = 110 degrees
the middle number; put the values in order from lowest to highest, then find the number that is exactly in the middle
sendo a função f(x) = 4x³ +8x² - 2 . x + 13, determine o valor de 9.f (3)
Answer:
The value of 9f(3) is 1683.
Step-by-step explanation:
This is a compound function, so let's call it [tex]g[/tex], where it is equal to:
[tex]g = 9*f(3)[/tex]
To solve it, we need to find [tex]f(3)[/tex] and apply it on the expression above, this is done below:
[tex]f(3) = 4*(3)^3 + 8*(3)^2 - 2*3 + 13\\f(3) = 4*27 + 8*9 - 6 + 13\\f(3) = 108 + 72 + 7\\f(3) = 187\\[/tex]
Applying it on [tex]g[/tex] we have:
[tex]g = 9*187 =1683[/tex]
Answer:
1,863
Step-by-step explanation:
First thing to do here is to substitute 3 for the value of x
f(3) =4)3)^3 + 8(3)^2 -2(3) + 13
= 4(27) + 8(9) -6 + 13
= 108 + 72 + 7 = 207
we now multiply this result by 9
= 9 * 207 = 1,863
SUBJECT: Mathematic
ASSIGNMENT
The diagram below shows a cylindrical moulding tool of diameter 16cm with a cylindrical hole of diameter 10cm. The height of the cylinder is 18cm and the hole is 6cm deep. Calculate the volume of the tool.
The height of a right circular cone is 6cm and its radius is 8cm.
Calculate its curved surface area.
Calculate the volume of the cone.
Answer:
Section A
Volume of the cylindrical tool = 1413.72cm³
Section B
1) Curved Surface Area of the right circular cone = 251.33cm²
2) Volume of the right circular cone = 402.12cm³
Step-by-step explanation:
Section A
We are asked to find the volume of the cylindrical moulding tool.
Volume of a cylinder = πr²h
From the question, the cylindrical tool had a diameter of 10cm. This means the radius of the tool = Diameter ÷ 2 = 10cm ÷ 2 = 5cm
The height of the cylindrical tool = 18cm
Volume of the cylindrical tool = π × (5cm)² × 18cm
1413.7166941cm³
Approximately = 1413.72cm³
Section B
The height of a right circular cone is 6cm and its radius is 8cm.
1) Calculate its curved surface area.
The formula for the curved surface area of a right circular cone =
πrl
r = radius = 8cm
h = height = 6cm
l = √(r² +h²) = √(8² + 6²) = √100
l = 10cm
The curved surface area = πrl
= π × 8cm × 10cm
= 251.33cm²
2) Calculate the volume of the cone.
The formula for the volume of a cone=
1/3πr²h
radius (r) = 8cm
height (h) = 6cm
1/3πr²h
1/3 × π × 8² × 6
= 402.12cm³
please help i don’t understand what so ever
Answer:
x=6
Step-by-step explanation:
Because of the Pythagorean theorem, you know that the square of the two legs of a right triangle will be equal to the square of the hypotenuse. Conversely, the square of one of the legs will be equal to the square of the other leg subtracted from the square of the hypotenuse. Therefore:
[tex]x^2=10^2-8^2 \\\\x^2=100-64\\\\x^2=36\\\\x=6[/tex]
Hope this helps!
Answer:
6
Step-by-step explanation:
By Pythagoras theorem
10^2 = 8^2 + x^2
100= 64 + x^2
X^2 =100-64
X^2= 36
[tex]x = \sqrt{36} \\ x = 6[/tex]
Hope this helps..
PLSSSSS HELPPP!!!!!!! PLLLLLLSSSSSS!!!!!! 20 POINTSSSSSS!!!!!! PLSSSS HELPPP!
Jamie has two similar rectangular boxes. If the sides of one box are three times the lengths of the corresponding sides of the other box, which one of the following is true? *
a. The volume of one box is 3 times the volume of the other.
b. The volume of one box is 6 times the volume of the other.
c. The volume of one box is 9 times the volume of the other.
d. The volume of one box is 27 times the volume of the other.
Answer:Box A contains 13.75 cubic feet more space than Box B. I just took the test. hope this helps ;)
Step-by-step explanation:
B^7 divided b^4 simplified
Answer:
[tex] = {b}^{3} [/tex]
Step-by-step explanation:
[tex] \: \: \: \: \: \: \: \frac{ {b}^{7} }{ {b}^{4} } \\ = {b}^{7 - 4} \\ = {b}^{3} [/tex]
hope this helps
brainliest appreciated
good luck! have a nice day!
the lines below are perpendicular. If the slope of the green line is 3/2, what is the slope of the red line?
A. 2/3
B. -2/3
C. -3/2
D. 3/2
Answer:
-2/3
Step-by-step explanation:
Perpendicular slopes have lines that multiply to -1
m* 3/2 = -1
Multiply each side by 2/3
m* 3/2 * 2/3 = -1 * 2/3
m = -2/3
The slope of the perpendicular line is -2/3
Answer:
The answer is B
I use an online graphing calculator called Desmos. You should check it out some time :)
No rush. I need help on this question. I need an explanation pleaseeeeee. Thank you in advance!
Answer:
1) 275
2)60
Step-by-step explanation:
1) 55 x 5 =275
2) 12 x 5 = 60
Hope it helps!
Answer:
2 vans and 7 busses
Step-by-step explanation:
Let x=# of busses
Let y=# of vans
55x+12y=409
x=y+5
55(y+5)+12y=409
55y+275+12y=409
67y+275=409
134=67y
y=2
There were two vans, and y+5 (7) busses
Each letters from I to W is written on a separate index card and placed in a box. Which ratio represents the probability that a letter in the word MILK will be selected on the first try?
Answer:
Ratio = 4 : 15 or
[tex] \frac{4}{15} [/tex]
Step-by-step explanation:
Here letters from I to W are written on a separate index card.
I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W
Counting the letters, they are 15 in number.
To find the probability that a letter in the word MILK will be selected on first try, we'll get the following:
Possible event / total number
Since the word MILK contains 4 letters, the probability =
[tex] \frac{4}{15} [/tex]
Therefore, ratio that represents the probability that a letter in the word MILK will be selected on the first try is 4 : 15
Factor each polynomial using the difference of two squares patt
square trinomial pattern.
x² – 9
Answer:
(x+3)(x-3)
Step-by-step explanation:
It is a difference of squares so it is sqrt of x^2 gives x and sqrt of 9 gives +3, -3. So we get (x+3)(x-3).
Graph the like that represents this equation
Answer: The answers are in the steps hope it helps.
Step-by-step explanation:
First solve or the equation and let it be in slope intercept form
y + 2 = 1/2( x + 2) apply the distributive property first
y + 2= 1/2x + 1
-2 -2
y= 1/2x -1 is not in slope intercept form so you could put in any number for x and five y.
This are the points you could plot then draw a straight line between them.
x y
0 -1
2 0
4 1
6 2
8 3
10 4
-2 -2
-4 -3
-6 -4
-8 -5
-10 -6
In ΔIJK, the measure of ∠K=90°, KI = 5.3 feet, and JK = 2.1 feet. Find the measure of ∠I to the nearest tenth of a degree. I
Answer:
[tex]\angle I = 21.6 ^\circ[/tex] is the correct answer.
Step-by-step explanation:
Please refer to the attached figure.
[tex]\triangle IJK[/tex] is shown with the following measurements:
[tex]\angle K = 90^\circ[/tex]
Side KI = 5.3 ft
Side JK = 2.1 ft
To find : [tex]\angle I[/tex] = ?
Using trigonometric identity for tangent of an angle:
[tex]tan\theta = \dfrac{\text{Perpendicular}}{\text{Base}}[/tex]
Here [tex]\theta = \angle I[/tex]
Perpendicular is side JK.
Base is side KI.
Putting the values in above formula:
[tex]tan\theta = \dfrac{\text{JK}}{\text{KI}}\\\Rightarrow tan\theta = \dfrac{2.1}{5.3}\\\Rightarrow tan\theta = 0.3962\\\Rightarrow \theta = 21.6^\circ[/tex]
Hence, [tex]\angle I = 21.6 ^\circ[/tex] is the correct answer.
help please and thank you
What is the y intercept of the function f(x)= -2/9x + 1/3?
Answer:
1/3
Step-by-step explanation:
plug in 0 for x
0 * anything = 0 (cancels out the -2/9) and you're left with 1/3
Keenan currently does a total of 888 pushups each day. He plans to increase the number of pushups he does each day by 222 pushups until he is doing a total of 303030 pushups each day. Which equation can we use to determine xxx, the number of days that it will take Keenan to reach his goal? Choose 1 answer: Choose 1 answer:
Answer:
222x + 888 = 303030
Step-by-step explanation:
If he raises the amount of push-ups he does by 222, then we can put the x with it, which represents the number of days. Since we are adding onto the 888 a day we can put that without the variable. If you were to solve this equation you would get the amount of days it would take to reach 303030 push-ups a day.
Hope this helps!
Answer:
8+2x=30
Step-by-step explanation:
did it on khan its correct
what is the midpoint of the segment shown below (-6,-2) (-1,5)
Answer:
(-3.5,2.5)
Step-by-step explanation:
[tex]m=\left( \dfrac{-6+-1}{2},\dfrac{-2+5}{2} \right)=\left( \dfrac{-7}{2},\dfrac{3}{2}\right)=\left( -3.5,2.5 \right)[/tex]
Hope this helps!
13 is 23 less than 15 times a number
Answer:
13 = 15(x) - 23
x = 12/5 or 2 2/5
People pay to visit a stately home [tickets age 16 and over : £18.60 ..under 16:£12.80] 155 people pay and 49 of these people are under 16. How much money is collected
Answer: £2598.80
Step-by-step explanation:
Let those under 16 be x
Those over 16 be y
49 + y = 155
y = 155-49
y = 106 = over 16
for over 16, y * 18.60
= 106 * 18.60 = 1971.60
For under 16, x * 12.80
= 49 * 12.80 = 627.20
Perform the indicated operation.
15 - 12
3
-3
-27
27
Answer:
3
Step-by-step explanation:
15-12
This is 12 taken away from 15
00000000 _ 000000
0000000 000000 000
15 marbles -- 12 marbles = 3 marbles
Please simplify then determine the value of the polynomial when n=3 and when n=2.
a) (5n^2 + 3n -4) + (-3n^2 + 4n -1)
b) (7n^2 - 5n - 2) - (-n^2 + 6n + 8)
please do a step-by-step explination if needed. i will make sure to give you brainliest.
Answer:
Simplified Expression a ) 2n^2 + 7n - 5,
Simplified Expression b ) 8n^2 - 11n - 10,
When n = 3 part a ) 34,
When n = 2 part a ) 17,
When n = 3 part b ) 29,
When n = 2 part a ) 0
Step-by-step explanation:
Consider the " simplification " process at hand;
[tex]a ) (5n^2 + 3n -4) + (-3n^2 + 4n -1),\\5n^2+3n-4-3n^2+4n-1,\\5n^2-3n^2+3n+4n-4-1,\\\\Simplified Expression = 2n^2+7n-5[/tex]
[tex]b ) (7n^2 - 5n - 2) - (-n^2 + 6n + 8),\\7n^2-5n-2+n^2-6n-8,\\\\Simplified Expression = 8n^2-11n-10[/tex]
For each part ( a and b ) I removed the ( ) and grouped like elements to receive the simplified expression;
Value of each polonomial;
[tex]a ) 2n^2 + 7n - 5,\\2 * ( 3 )^2 + 7 * ( 3 ) - 5,\\34\\\\2 * ( 2 )^2 + 7 * ( 2 ) - 5\\17[/tex]
[tex]b ) 8n^2 - 11n - 10,\\8 * ( 3 )^2 - 11 * ( 3 ) - 10,\\29\\\\8 * ( 2 )^2 - 11 * ( 2 ) - 10,\\0[/tex]
Each expression was solved through substitution and algebra.
" Simplified " Solution - See in answer above
* I hope the answer wasn't too confusing, for further information look through my response thoroughly