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?

Answers

Answer 1

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.


Related Questions

What is the solution to the equation Negative (5 minus (a + 1)) = 9 minus (5 minus (2a minus 3))? a = –5 a = –3 a = 3 a = 5

Answers

Answer:

a = -5

Step-by-step explanation:

negative (5 minus (a + 1)) = 9 minus (5 minus (2a minus 3)) can be expressed mathematically as follows.

- (5 - (a + 1)) = 9 - (5 - (2a - 3))

using the principle of PEMDAS, all the parenthesis values are first solved

- (5 - a - 1) = 9 - (5 - 2a + 3)

-5 + a + 1 = 9 - 5 + 2a - 3

collect like terms

-5 + 1 - 9 + 5 + 3 = 2a - a

-5 = a Therefore,

a = -5

Answer:

-5

Step-by-step explanation:

5+(8×5)+72÷8 !? what is the answer please ​

Answers

Answer:

54 is the answer

Step-by-step explanation:

5+(8x5)+72/8

5+40+9

54

5 + 40 + 72\8

5 + 40 + 9

45 + 9

54

At which root does the graph of f(x) = (x – 5)3(x + 2)2 touch the x-axis?
-5
-2
Ο Ο Ο Ο
2
5

Answers

Answer:

At x = -2 the graph of this polynomial will touch the x-axis.

Step-by-step explanation:

Recall the behavior difference between power functions of even and odd power. Odd powers are associated with the crossing of the x-axis, while even powers are associated with "touching" of the x axis.

in this cases, since they give you the function in factor form, the actual roots (x-values where the function adopts value zero) of the function are evident :

[tex]f(x)=(x-5)^3\, (x+2)^2[/tex]

It has a root at x = 5 [notice that at such x-value the factor (x-5) becomes zero], and this root is of multiplicity "3" (given by the power associated with the binomial factor for this root)

and has another root at x = -2  [notice that at such x-value the factor (x+2) becomes zero], and this root is of multiplicity "2" (given by the power associated with the binomial factor for it)

It is just the second root analyzed the one that shows an even power (2) associated to its binomial factor, and therefore it is at x= -2 that the graph of this function will show as "touching" the x axis.

Answer ASAP, please!!!!!! Will mark brainliest!!!!! 25 points!!!!!
Explain how the Distributive Property can be used to expand the expression on the left side of the equation.
3(x + 4) = 36.
A. Add 3 to each term inside the parentheses.
B. Subtract 3 from each term inside the parentheses.
C. Multiply each term inside the parentheses by 3.
D. Divide both terms inside the parentheses by 3.

Answers

Answer:

C

Step-by-step explanation:

The 3 is directly outside the parentheses, meaning you need to distribute the 3 to the x and the 4 because they are inside the parentheses. There is no addition, subtraction, or division involved in this so C is correct.

Answer:

C

Step-by-step explanation:

i took the test

Help please this is due in a couple minutes!!!! Anyone know the answer??!!!?

Answers

Answer:

the second one

Step-by-step explanation:

correct me if it is wrong

please help thank youuu!

Answers

Answer: D. All interior angles and all sides are congruent.

Step-by-step explanation:

If it is a regular polygon, then all angles and sides have to be congruent.

The interior angles aren’t congruent to the exterior angles.

Not all angles have to be congruent, in regular or irregular.

Since this polygon has 25 sides, opposite pairs aren’t parallel because there are an odd number of sides. That means there are no opposite pairs.

Answer:

D

Step-by-step explanation:

true or false ? why and why not ?


8a - (8a - 8) is equivalent to 8

Answers

Answer:

True

Step-by-step explanation:

Apply the distributive property

8a-(8a)- -8

Multiply 8 by -1

8a-8a- -8

Multiply -1 by -8

8a-8a+8

Simplify by adding terms

Subtract 8a from 8a

0+8

Add 0 and 8

8

Hope this helps :)

gbhujiklbvnhjkml dxfcgvhj

Answers

Answer:

C.  2 1/2

Step-by-step explanation:

Since there is a distance of 6 1/2 units, you have to add and subtract 6 1/2 from the number.

-4 - 6 1/2 = -10 1/2

-4 + 6 1/2 = 2 1/2

Looking at the answer choices, 2 1/2 can represent point Q.

The perimeter of the given triangle is

Answers

Answer:

~73.68

Step-by-step explanation:

In the right triangle with one angle = 45 deg

=> Isosceles right triangle

=> a = b = hypotenuse/sqrt(2) = (12sqrt(2))/sqrt(2) = 12

In other right triangle with 3 sides are a, c, and d, we have:

sin (30 deg) = a/d

=> d = a/sin(30 deg) = 12/(1/2) = 12 x 2 = 24

Othwise, cosine (30 deg) = c/d

=> c = d x cos(30 deg) = 24 x sqrt(3)/2 = 12sqrt(3)

=> The perimeter of the biggest triangle is calculated by:

P = 12sqrt(2) + b + c + d = 12sqrt(2) + 12 + 12sqrt(3) + 24 = ~73.68

Hope this helps!

find the value of each trigonometric ratio part 3​

Answers

Answer:

hope this helps you

Given the points (-2,-4) and (-3,-5) what is the slope

Answers

Answer:

1/1

Step-by-step explanation:

Inscribed Angles - What is the value of x? WILL GIVE BRAINLIEST!

Answers

Answer:

18

Step-by-step explanation:

hope it helps!

What is the leading coefficient of the polynomial f(x)f(x) defined below? f(x)=−3x^4−10x^3

Answers

Answer:

9x^8

Step-by-step explanation:

f(x) is a binomial.  Multiplying a binomial by itself results in a trinomial.  In this problem we need ONLY to specify what the leading coefficient (coefficient of this trinomial product) is.

Here this is obtained by squaring the coefficient −3x^4.  We get"

(-3)^2*(x^4)^2  =  9x^8

IThe first three terms of a sequence are given. Round to the nearest thousandth (if
necessary).
72, 24, 8, ...
Find the 8th term.

Answers

Answer: the eight term is 8/243

Step-by-step explanation:

Each term in this geometric sequence is equal to the previous term, divided by 3.

72,24, 8

a = 72, r = 1/3

a = first term, r is common ratio

tn = ar^n-1

t8 = 72÷ 3^8–1

t8 = 72÷ 3^7

= 72/ 3^7

= 8/243

Can you please help

Answers

Pyramid
B=36
h=4
(36*4)/3=48

Prism
B=144
h=3
V= (bh)= 432

answer= 432+48 =480


Which shows the fractions in order from greatest to least?

A.5/10,1/4,3/4,5/7
B. 3/4,5/7,5/10, 1/4
C. 5/10,5/7,3/4,1/4
D.1/4, 3/4, 5/7,5/10

Answers

Answer:

Step-by-step explanation:

D

part 3. Find the value of the trig function indicated, use Pythagorean theorem to find the third side if you need it.​

Answers

Answer:  [tex]\bold{9)\ \sin \theta=\dfrac{1}{3}\qquad 10)\ \sin \theta = \dfrac{4}{5}\qquad 11)\ \cos \theta = \dfrac{\sqrt{11}}{6}\qquad 12)\ \tan \theta = \dfrac{17\sqrt2}{26}}[/tex]

Step-by-step explanation:

Pythagorean Theorem is: a² + b² = c²   , where "c" is the hypotenuse

[tex]9)\ \sin \theta=\dfrac{\text{side opposite of}\ \theta}{\text{hypotenuse of triangle}}=\dfrac{4}{12}\quad \rightarrow \large\boxed{\dfrac{1}{3}}[/tex]

Note: 4² + (8√2)² = hypotenuse²   →   hypotenuse = 12

[tex]10)\ \sin \theta=\dfrac{\text{side opposite of}\ \theta}{\text{hypotenuse of triangle}}=\dfrac{16}{20}\quad \rightarrow \large\boxed{\dfrac{4}{5}}[/tex]

Note: 12² + opposite² = 20²   →   opposite = 16

[tex]11)\ \cos \theta=\dfrac{\text{side adjacent to}\ \theta}{\text{hypotenuse of triangle}}=\dfrac{\sqrt{11}}{6}\quad =\large\boxed{\dfrac{\sqrt{11}}{6}}[/tex]

Note: adjacent² + 5² = 6²   →   adjacent = √11

[tex]12)\ \tan \theta=\dfrac{\text{side opposite of}\ \theta}{\text{side adjacent to}\ \theta}=\dfrac{17}{13\sqrt2}\quad =\large\boxed{\dfrac{17\sqrt2}{26}}[/tex]

Note: adjacent² + 7² = (13√2)²   →   adjacent = 17

a rectangular inflatable swimming pool is 2 [tex]\frac{4}{5}[/tex] yards long, 2 yards wide, and [tex]\frac{3}{5}[/tex] yard tall. What is the volume of the pool? Round to the nearest tenth

Answers

Answer:

3.4 yd^3

Step-by-step explanation:

The volume is

V = l*w*h

V = 2 4/5 * 2 * 3/5

Changing the mixed number to an improper fraction

2 4/5 = ( 5*2+4)/5 = 14/5

V =  14/5 * 2 * 3/5

  = 84/25

Changing back to a mixed number

3*25 = 75 with 9 left over

3 9/25

3.36 yd^3

To the nearest tenth

3.4 yd^3

Answer: 3.4 yards cubed, after rounding.

Step-by-step explanation:

To find the volume of a rectangular prism, use the following formula:

[tex]V = wlh[/tex], where w is the width, l is the length, and h is the height

Substitute the values given to you into the formula:

[tex]V = 2 * \frac{3}{5} * 2\frac{4}{5}[/tex]

Simplify the mixed number by multiplying both the numerator and denominator of 2/1 by 5 to get 10/5 and add it to the fraction to get 14/5.

[tex]V = \frac{2}{1} * \frac{3}{5} * \frac{14}{5}[/tex]

Now, multiply the numerators and denominators of the fractions and simplify:

[tex]V = \frac{2 * 3 * 14}{5 * 5}\\\\V = \frac{84}{25}\\\\\\V = 3.36[/tex]

The volume is 3.36 yards cubed. Round to the nearest tenth to get 3.4 yards cubed.

Help me with this question please

Answers

Answer:

x < 6

Step-by-step explanation:

There is an open circle ( no equals) at 6   and the line goes to the left

This means that it is less than 6

x < 6

please answer asap! A couple plans to have 5 children. The gender of each child is equally likely. Design a simulation involving 125 trials that you can use to model the genders of the children. Write your answers as numbers.

Answers

Step-by-step explanation:

The gender of a child which is either a boy or a girl is determined by the XX-chromosomes, or XY-chromosomes.

Since the couple plan to have 5 children, the chance of a child being a boy is equal to the chance of it being a girl - the chances are 50/50.

What we do to achieve our aim is to run a simulation that would add an X or Y to an X for all 5 children.

Doing this 125 times, we obtain the number of trials we desire.

For each trial, we get for each child, C:

C1: X + (X or Y)

C2: X + (X or Y)

C3: X + (X or Y)

C4: X + (X or Y)

C5: X + (X or Y)

Since the chance of having an X is equal to the chance of having a Y, they equal probability, which is 0.5 for each.

Can someone plz help me out! With this problem I really need help ASAP! I will mark you as brainiest! Help help ASAP!

Answers

Answer:

John = 82 Billy = 82 Gregg = 80 Bob = 55

Step-by-step explanation:

John = (3x38)+(2x0)-(2x8)-(2x8)

Billy = (3x30)+(2x4)-(2x3)-(2x5)

Gregg = (3x30)+(2x3)-(2x4)-(2x4)

Bob = (3x25)+(2x6)-(2x9)-(2x7)

HELP ASAP PLEASE!!! Explain how you will benefit most from improving your math skills.

Answers

Answer:

Some of the most lucrative jobs are all about math. Most engineering fields are all about sharp math skills, whether it’s civil and mechanical or software engineering. Working in finance also obviously involves a lot of math, and what better way to make money than working in the field that’s all about money? You can also become a statistician or actuary; it’s not easy to find good statisticians, despite the need for them. If you want to earn good money, then you do need good math skills.Then again, you could use math in life anyway.

Step-by-step explanation:

For the function y = -2x + 4, the input is 3. What is the output?

Answers

Answer:

y = -2

Step-by-step explanation:

Plug in 3 for x

y = -2 (3) + 4

y = -6 + 4

y = -2

I hope this helps :))

Over the past ten years, the town's population doubled in size. The population is currently 12,000. What was the population ten years ago? Which of the following represents the given word problem if "P" represents the population ten years ago? 2(P + 10) = 12,000 2P = 12,000 P = 2(12,000)

Answers

Answer:

2p=12,000

Step-by-step explanation:

Triangle A B C is shown. Angle B C A is a right angle. The length of hypotenuse A B is 26, the length of A C is 10, and the length of B C is 24. Given right triangle ABC, what is the value of tan(A)? Five-thirteenths Twelve-thirteenths Twelve-fifths Thirteen-twelfths

Answers

Answer:

The right option is twelve-fifths

Step-by-step explanation:

Given a right angle triangle ABC as shown in the diagram. If ∠BCA = 90°, the hypotenuse AB = 26, AC = 10 and BC = 24.

Using the SOH, CAH, TOA trigonometry identity, SInce we are to find tanA, we will use TOA. According to TOA;

Tan (A) = opp/adj

Taken BC as opposite side since it is facing angle A directly and AC as the adjacent;

tan(A) = BC/AC

tan(A) = 24/10

tan(A) = 12/5

The right option is therefore twelve-fifths

Answer:

The correct answer is option C. 12/5

Step-by-step explanation:

Hope this helps!

Brainliest would be greatly appreciated :D

i need help pls asap!!

Answers

Answer:

No, Electric Pole is 40 ft

Step-by-step explanation:

tan 66.8° = [tex]\frac{x}{15}[/tex]

x = 35

but that is from the top of Danny, so you need to add 5 (his height)

Electric Pole is 40 ft

How much water can a rectangular pool hold if it has a length of 30 feet, a width of 25 feet, and is 8 feet deep?

Answers

Answer:

44,886 gallons

Step-by-step explanation:

We need to find the volume

V = l*w*h

V = 30ft*25ft*8ft

V =6000 ft^3

We know that 1 ft^3 = 7.481 gallons

6000 ft^3 * 7.481 gallons/1 ft^3 = 44886 gallons

Answer:

44,883 gallons

Step-by-step explanation:

The amount of water the pool can hold can be found by calculating the volume of the pool.

We know that the pool is rectangular, and it is a three dimensional shape (3 dimensions: length, width and depth). Therefore, we can use the formula for finding the volume of a rectangular prism:

V=l*w*h

We know the length is 30 feet and the width is 25 feet. The height is also the depth, so the height is 8 feet.

l= 30 feet

w=25 feet

h= 8 feet

Substitute these values into the formula.

V= 30 feet * 25 feet * 8 feet

Multiply the numbers together.

V= (30 feet * 25 feet) * 8 feet

V= 750 feet^2 * 8 feet

V=6000 feet^3

Now, let's find how many gallons the pool can hold.

1 ft^3 is equal to 7.4805 gallons. Therefore, we can multiply 6000 ft^3 and 7.4805

6000 ft^3 * 7.4805 gallons/1 ft^3

6000* 7.4805 gallons

44,883 gallons

The pool can hold 44,883 gallons of water.

What is 2 with an exponent of -2 equal to?

Answers

Answer:

1/4

Step-by-step explanation:

Answer:

[tex] \boxed{\frac{1}{4} } [/tex]

Step-by-step explanation:

[tex]{2}^{ - 2} = \frac{1}{ {2}^{2} } \\ \\ \: \: \: \: \: \: \: \: \: = \frac{1}{4} [/tex]

[tex] Negative \: exponent \\ \\ = > {a}^{-x} = \frac{1}{{a}^{x}} [/tex]

Can someone please explain what I did wrong here? Thank you!

Answers

Answer: The total number of ways is wrong. Since there is 12 members, each of them could be the president, vice president, etc.

Step-by-step explanation:

What can be concluded about the sequence 19, 15, 11, 7, . . . represented on the graph? Check all that apply. The common difference of the sequence is the same as the slope of the graph. The slope of the graph is –4. The next term in the sequence is represented by point (4, 3). f(x) = –4x + 19 represents the sequence. An infinite number of points can be determined to follow this sequence.

Answers

Answer:

3, -1

Step-by-step explanation:

the answer is A,B,E

i took the test

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