can someone please help with answer and explanation
9514 1404 393
Answer:
(x, y) = (3, 12)
Step-by-step explanation:
The first step in any problem solving is to look at the problem. Here, we see that the first equation can be reduced to standard form by dividing it by 2. This would give both terms a coefficient of 1.
We see that the second equation already has a variable with a coefficient of 1.
When solving a system by substitution, it can save some effort if you start by finding a variable with a coefficient of 1 or -1. Since we see that in the second equation, we choose to solve the second equation for y:
y = 4x . . . . . . . add 4x to both sides of the second equation
Now, we have an expression for y that we can substitute into the first equation.
2x +2(4x) = 30 . . . . substitute for y
10x = 30 . . . . . . . . simplify
x = 3 . . . . . . . . . . divde by 10
y = 4(3) = 12 . . . . . find y using y=4x
The solution is (x, y) = (3, 12).
__
Additional comment
I doesn't matter what variable gets substituted. The purpose of the exercise is to reduce the number of variables in the equation. Here, we start with an equation that has 2 variables. Substituting for one of them gives an equation with only one variable, a lot easier to solve.
You don't have to find an expression for the "bare" variable. We could solve the second equation for 2x, for example: 2x = y/2, then substitute for 2x in the first equation: y/2 +2y = 30 ⇒ y = (2/5)(30) = 12. Or, we could solve the first equation for 2x and substitute into the second: 2x=30-2y, y-2(2x) = 0 ⇒ y-2(30-2y) = 0 ⇒ y = 60/5 = 12.
The substitution property of equality says you can make any substitution of equal values anywhere. "butter = margarine" means you can substitute butter for margarine, or vice versa, wherever you may wish.
A married couple had a combined annual income of $81,000. The wife made $9000 more than her husband. What was each of their incomes?
Step-by-step explanation:
Let the husband's income be x
Wife's income be x + 9000
X + X + 9000 = 81000
2X + 9000 – 9000 = 81000 – 9000
2X= 72000
X = 36000
Husband, 36000,
Wife, 9000+36000, 45000
From the picture, two cylindrical glasses of the same capacity. Find the diameter length (X) of a small glass of water.
8
12
14
10
Answer:
12
Step-by-step explanation:
πr²h=πr²h
π(4.5)²*10=π(x/2)²4.9
is y=x^2 a proportional relationship?
is y=2+x a proportional relationship?
is y=2/x a proportional relationship?
is y=2x a proportional relationship?
Answer:
is y=x^2 a proportional relationship?
[tex]{ \sf{yes. \: constant \: of \: proportionality = 1}}[/tex]
is y=2+x a proportional relationship?
[tex]{ \sf{no. \: unless \: y \: is \: proportinal \: to \: (2 + x)}}[/tex]
is y=2/x a proportional relationship?
[tex]{ \sf{yes. \: where \: proportianality \: constant \: is \: 2}}[/tex]
is y=2x a proportional relationship?
[tex]{ \sf{yeah. \: constant \: is \: 2}}[/tex]
I need help finding what U stand for
Answer:
u = 18
Step-by-step explanation:
The two angles 3u and u+36 are equal so
3u = u+36
Subtract u from each side
3u -u = u+36-u
2u = 38
Divide by 2
2u/2 = 36/2
u = 18
The volume of the triangular prism is 54 cubic units.
What is the value of x?
5
9
4
3
Answer: the answer is 3
Step-by-step explanation:
I just took the test
Click on the graph where a transformation occurred that doesn't preserve the physical characteristics of rectangle FGHI.
Answer:
Click the graph in Quadrant 1
Step-by-step explanation:
This graph is bigger in side length.
One angle of an isosceles triangle is 16 what are the other 2 angles
Answer:
other two angle will be
82
as 82+82+16 = 180'
An insurance company estimates the probability of an earthquake in the next
year to be 0.0012. The average damage done by an earthquake it estimates to be
$60,000. If the company offers earthquake insurance for $100, what is their expected
value of the policy?
Answer:
- 27.88
Step-by-step explanation:
Probability of earthquake = 0.0012
P(earthquake). = 0.0012
P(no earthquake) = 1 - p(earthquake) = 1 - 0.0012 = 0.9988
X ____ 60,000 ______ - 100
P(X) ___ 0.0012 _____ 0.9988
The expected value of the policy :
E(X) = Σx*p(x)
E(X) = (0.0012 * 60000) + (0.9988 * - 100)
E(X) = 72 - 99.88
E(X) = - 27.88
A hot air balloon is rising vertically with a velocity of 12.0 feet per second. A very small ball is released from the hot air balloon at the instant when it is 1120 feet above the ground. Use a(t)=−32 ft/sec^2 as the acceleration due to gravity.
Required:
a. How many seconds after its release will the ball strike the ground?
b. At what velocity will it hit the ground?
Answer:
Here we only need to analyze the vertical motion of the ball.
First, because the ball is in the air, the only force acting on the ball will be the gravitational force (we are ignoring air resistance), then the acceleration of the ball is equal to the gravitational acceleration, so we have:
a(t) = -32 ft/s^2
where the negative sign is because this acceleration is downwards.
To get the velocity equation, we need to integrate over the time, so we get:
v(t) = (-32 ft/s^2)*t + V0
where V0 is the initial velocity of the ball. In this case, the initial velocity of the ball will be the velocity that the ball had when it was dropped, which should be the same as the velocity of the hot air ballon, so we have:
V0 = 12 ft/s
Then the velocity equation of the ball is:
v(t) = (-32 ft/s^2)*t + 12 ft/s
To get the position equation we integrate again:
p(t) = (1/2)*(-32 ft/s^2)*t^2 + (12 ft/s)*t + H0
Where H0 is the initial height. We know that the ball was released at the height of 1120 ft, then we have:
H0 = 1120 ft.
Then the position equation is:
p(t) = (-16 ft/s^2)*t^2 + (12 ft/s)*t + 1120ft
a) How many seconds after its release will the ball strike the ground?
The ball will strike the ground when its position equation is equal to zero, then we need to solve:
p(t) = 0 ft = (-16 ft/s^2)*t^2 + (12 ft/s)*t + 1120ft
This is just a quadratic equation, the solutions are given by Bhaskara's formula, so the solutions for t are:
[tex]t = \frac{- 12ft/s \pm \sqrt{(12 ft/s)^2 - 4*(-16ft/s^2)*(1120 ft)} }{2*(-16ft/s^2)}[/tex]
We can simplify that to get:
[tex]t = \frac{-12ft/s \pm 268ft/s}{-32ft/s^2}[/tex]
So we have two solutions:
[tex]t = \frac{-12ft/s + 268ft/s}{-32ft/s^2} = -8s[/tex]
[tex]t = \frac{-12ft/s - 268ft/s}{-32ft/s^2} = 8.75s[/tex]
The negative solution does not make sense, then the correct solution is the positive one.
We can conclude that the ball will hit the ground after 8.75 seconds.
b) At what velocity will it hit the ground?
We already know that the ball strikes the ground 8.75 seconds after it is released.
The velocity at it hits the ground is given by the velocity equation evaluated in that time:
v(8.75 s) = (-32 ft/s^2)*8.75s + 12 ft/s = -268 ft/s
Triangle A B C is shown. The included side between ∠A and ∠C is side . The included side between ∠A and ∠B is side . The included side between ∠C and ∠B is side .
Answer:
AC, AB, BC
Step-by-step explanation:
Given
[tex]\triangle ABC[/tex]
Required
Name the sides
(a) [tex]\angle A[/tex] and [tex]\angle C[/tex]
This represents side [tex]AC[/tex]
(b) [tex]\angle A[/tex] and [tex]\angle B[/tex]
This represents side [tex]AB[/tex]
(c) [tex]\angle C[/tex] and [tex]\angle B[/tex]
This represents side [tex]CB[/tex]
i.e. we simply bring the name of both angles together
Answer:
AC, AB, BC
Step-by-step explanation:
solve: x^2-x-12÷x+5 ≥ 0
Answer:
Step-by-step explanation:
x3−x2+5x−12
x
≥0
Let's find the critical points of the inequality.
x3−x2+5x−12
x
=0
x3−x2+5x−12=0(Multiply both sides by x)
(Use cubic formula)
x=1.836169
Check possible critical points.
x=1.836169(Works in original equation)
Critical points:
x=1.836169(Makes both sides equal)
x=0(Makes left denominator equal to 0)
Check intervals in between critical points. (Test values in the intervals to see if they work.)
x<0(Works in original inequality)
0<x≤1.836169(Doesn't work in original inequality)
x≥1.836169(Works in original inequality)
Answer:
x<0 or x≥1.836169
Based on the Nielsen ratings, the local CBS affiliate claims its 11:00 PM newscast reaches 41% of the viewing audience in the area. In a survey of 100 viewers, 36% indicated that they watch the late evening news on this local CBS station.Reference: 10_02What is your decision if the calculated value of z is -1.02 and the
Answer:
at 15.39% that should not be sufficient to reject the Null
= "Fail to reject the Null hypothesis"
Step-by-step explanation:
z = -1.02 (L)0.15386 (R)0.84614
84.61% / 15.39%
1. Đường kính của một loại trục máy là một đại lượng ngẫu nhiên có phân phối chuẩn N (μ = 250mm, σ2 = 25mm2). Trục máy được gọi là hợp quy cách nếu đường kính từ 245mm đến 255mm. Cho máy sản xuất 100 trục. Tính xác suất để:
a. Có 50 trục hợp quy cách.
b. Có không quá 80 trục hợp quy cách
Answer:
cannot understand the language man
but please follow
Which of the following expressions are equivalent?
I. 5a6
II. 30a
III. a6 + a6 + a6 + a6 + a6
IV. 6a5
Answer:
5а⁶=а⁶+а⁶+а⁶+а⁶+а⁶
~~~~~~~~
What is 1/8+1/4 whats the answer
Which of the following would increase the width of a confidence interval for a population mean? Choose the correct answer below. A. Increase the level of confidence B. Decrease the sample standard deviation. C. Increase the sample size D. All of the above
Answer:
A. Increase the level of confidence
Step-by-step explanation:
The margin of error is given by:
The margin of error is:
[tex]M = \frac{Ts}{\sqrt{n}}[/tex]
In which T is related to the level of confidence(the higher the level of confidence, the higher T is), s is the standard deviation of the sample and n is the size of the sample.
Increase the width:
That is, increasing the margin of error, as the width is twice the margin of error, the possible options are:
Increase T -> increase confidence level.
Increase s -> Increase the standard deviation of the sample.
Decrease n -> Decrease the sample size.
Thus, the correct answer is given by option A.
in order for the parallelogram to be a rhombus, x=?
[tex]\\ \large\sf\longmapsto x + 15 = 2x - 40 \\ \\ \large\sf\longmapsto x - 2x = - 40 - 15 \\ \\ \large\sf\longmapsto - x = - 55\\ \large\sf\longmapsto x = 55[/tex]
The value of x is 55 degrees.
What is rhombus?A rhombus is a diamond-shaped quadrilateral that has all four sides equal
What are the properties of a rhombus?The properties of a rhombus are:
Opposite angles are equal.All sides are equal and, opposite sides are parallel to each other.Diagonals bisect each other perpendicularly.Sum of any two adjacent angles is 180°According to the given question.
We have a rhombus.
Since, we know that the diagonals of the rhombus bisect the angles.
Therefore,
[tex](x+15)^{o} = (2x-40)^{o}[/tex]
Solve, the above expression for x.
[tex]\implies x +15 = 2x -40\\\implies 15+40 = 2x -x \\\implies 55 = x \\0r\ x = 55^{o}[/tex]
Hence, the value of x is 55 degrees.
Find out more information about rhombus here:
https://brainly.com/question/12189679
#SPJ2
I don’t understand the last 2
Nice job on getting the correct answer 144 for the first box. For anyone curious, this is found by multiplying the side lengths of the square. So 12*12 = 144.
======================================
All four sides are decreased by 5 meters. So we go from 12 meter sides to 12-5 = 7 meter sides.
The area of the square is found in the same way as earlier: We multiply the side by itself
area = side*side = 7*7 = 49 square meters
So you'll type 49 into the second box
=======================================
To find the amount of decrease, you subtract the two area values:
144 - 49 = 95 goes in the third box
This indicates that the area has decreased by 95 m^2
Algebra help needed. Overwhelmed with other papers. See attached
Answer:
Step-by-step explanation:
whitch answer how do you want us to answer
(a) Joe runs 12 miles in 84 minutes.
How many miles does he run per minute?
İmiles per minute
Step-by-step explanation:
We want to find how many miles per minute Joe runs. This means, we need to simplify the equation:
[tex]\frac{12 mi}{84 min}[/tex]
so that the number on the bottom is 1. How do we do that?
Simple.
Just divide 12 / 84
Answer:
Joe runs approx. 0.143 miles per minute.
The volume of the cylinder is V=1/3r^2h, where r is the radius and h is the height. if the radius of a cylinder is 3 inches and the height is 8 inches, which answer below best estimates it’s volume?
Answer:
75 inches
Step-by-step explanation:
with this we use change of subject
V=1/3
Pie=3.14
radius =3
height =8
so therefore
V=1/3 ×3.14×3×3×8
V=75.36
Solve. Justify your responses. Given:a║b and c║d, m∠ 4=35° Find: m∠1, m∠2, and m∠3
Answer <1 = 145
< 2= 35
<3 = 35
PLS MARK BRAINLIESTSTEPS BELOWStep-by-step explanation:
<1 + <4 = 180 (supplementary since you can find corresponding side and straight angle)
<1 = 180-35
=145 degrees
<2 =<4 corresponding angles
<2 = 35 degrees
<3 = 35 degree (corresponding to <2)
Define mean and median for a set of data
Answer:
The mean is the average number of a data set gotten by adding all the numbers then dividing by two.
the median is the middle number in a sorted set of data,either sorted in ascending order or descending order.
I hope this helps
To calculate mean:
• add up all the numbers,
• then divide by how many numbers there are.
Example:
Data: 5, 6, 10, 1
Add these all together, which is 22, then divide by 4 (because that is how many numbers there are), so:
the mean is 5.5
To calculate median:
Arrange your numbers in order.
Cross off numbers until you get to the middle.
If there is an even number of data, then find the two in the middle and find the middle of that.
Example:
Data: 5, 6, 10, 1
Arrange: 1, 5, 6, 10
So, the middle 2 are 5 and 6. In between these would be 5.5, so that is the median.
If the data was: 1, 5, 6, 8, 10,
then the median would be 6.
how to find the dot product of 1×3 vectors
Answer:
Since we know the dot product of unit vectors, we can simplify the dot product formula to a⋅b=a1b1+a2b2+a3b3. we can use the same formula, but with a3=b3=0, a⋅b=a1b1+a2b2.
Step-by-step explanation:
hope it will help uplease mark me brillientFarmer Dave harvested his corn. He stored 5/9 of his corn in one large silo and ¾ of the remaining corn in a small silo. The rest was taken to market to be sold.
a. What fraction of the corn was stored in the small silo?
b. If he harvested 18 tons of corn, how many tons did he take to market?
After storing 5/9 in the large silo there was 4/9 left ( 1-5/9 = 4/9)
A. Multiply 4/9 by 3/4:
4/9 x 3/4 = 12/36 = 1/3
1/3 of the corn was in the small silo.
B. 1-5/9 -1/3 = 4/9-1/3 = 4/9-3/9 = 1/9
1/9 of the corn went to market:
18 x 1/9 = 18/9 = 2
2 ton went to market.
Simplify the following expression.
(1565)
———-
(562)3
Solve for x
-3x = -15
A) x = -45
B) x = 5
C) x = -5
C-x=-5
Step-by-step explanation:
-3x=-15
or,-3x x =-15
or, x=-15÷3
therefore, x=-5
Find m∠F.
Find the answer to m∠F
Answer:
m∠F = 45°
Step-by-step explanation:
Notice the lengths of the given sides and the right angle. This is enough information to prove that this is a 45-45-90 triangle, or just basically a square cut diagonally.
Regardless if even just one side is given for a 45-45-90 triangle, all 45-45-90 triangles have one thing in common. The sides that form the right angle are equivalent and the hypotenuse is equal to one of the sides that form the right angle times the square root of two. I'm aware that it sounded confusing, as I'm awful at explaining, so just look at the picture I've attached instead of trying to understand my explanation that seemed like trying to learn a second language.
Look at the picture. See that FD = x times that square root of 2 and that DE = x. Now look back at your picture. It's connecting, now isn't it?
Now that we know that this is indeed a 45-45-90 triangle, we can confirm that m∠F = 45°
what equation shows a slope of 2/3 and a white intercept of 0, -2
y = 2/3 x - 2
Or
y + 2 = 2/3 ( x )
Answer:
y= 2/3x - 2
hope this helps :)