All categories

3 years ago

-3x-y=-17 4x + 2 y equals 20

1 answer:

4 0

-3x - y = -17
4x + 2y = 20

multiply one part of the equation so that we can be able to use the process of elimination.

(-3x - y = -17)2
4x + 2y = 20

Now we have:

-6x -2y = - 34
4x+2y= 20
------------------------
-2x = -14

Divide -2 on both sides.

-2x = -14
/-2       /-2

x = -7.

=============================================

To solve for y, we just have to substitute the value of x to any of the equation given above, that we feel comfortable with. And I'm going to choose this equation: 4x + 2y = 20

4x + 2y = 20

4(-7) + 2y = 20

-28 + 2y = 20

Add 28 on both sides

-28 + 2y = 20
+28          +28
---------------------
2y = 48
/2      /2

y = 24.

The last thing you would do is to check if the answers is correct.
All you have to do is plug in the values of x and y into both equations and see if they equal to one another.

You may have to do this by yourself :P

Anyways, if you have any questions about this topic, feel free to PM me or any other users interested. Thank you for being part of Brainly! Have a nice day!

You might be interested in

Answer these 2 questions please

Dmitry [639]

Where’s the question?

8 0

3 years ago

Read 2 more answers

For one Geometry test, Nancy correctly answered 18 questions. These correct answers gave her a percent score of 72%. In total, h

Brrunno [24]

Answer:

25 questions.

Step-by-step explanation:

Correct answer = 18

The percent score of the correct answers is 72%.

Let there are x questions in the test. So,

According to the given condition,

$72\%\ of\ x=18\\\\\dfrac{72}{100}x=18\\\\x=\dfrac{18\times 100}{72}\\\\x=25$

Hence, there were 25 questions in the geometry test.

4 0

3 years ago

Which statement describes the inverse of m(x) = x^2 – 17x?

DochEvi [55]

Given:

The function is

$m(x)=x^2-17x$

To find:

The inverse of the given function.

Solution:

We have,

$m(x)=x^2-17x$

Substitute m(x)=y.

$y=x^2-17x$

Interchange x and y.

$x=y^2-17y$

Add square of half of coefficient of y , i.e., $\left(\dfrac{-17}{2}\right)^2$ on both sides,

$x+\left(\dfrac{-17}{2}\right)^2=y^2-17y+\left(\dfrac{-17}{2}\right)^2$

$x+\left(\dfrac{17}{2}\right)^2=y^2-17y+\left(\dfrac{17}{2}\right)^2$

$x+\left(\dfrac{17}{2}\right)^2=\left(y-\dfrac{17}{2}\right)^2$ $[\because (a-b)^2=a^2-2ab+b^2]$

Taking square root on both sides.

$\sqrt{x+\left(\dfrac{17}{2}\right)^2}=y-\dfrac{17}{2}$

Add $\dfrac{17}{2}$ on both sides.

$\sqrt{x+\left(\dfrac{17}{2}\right)^2}+\dfrac{17}{2}=y$

Substitute $y=m^{-1}(x)$ .

$m^{-1}(x)=\sqrt{x+(\dfrac{189}{4}})+\dfrac{17}{2}$

We know that, negative term inside the root is not real number. So,

$x+\left(\dfrac{17}{2}\right)^2\geq 0$

$x\geq -\left(\dfrac{17}{2}\right)^2$

Therefore, the restricted domain is $x\geq -\left(\dfrac{17}{2}\right)^2$ and the inverse function is $m^{-1}(x)=\sqrt{x+(\dfrac{189}{4}})+\dfrac{17}{2}$ .

Hence, option D is correct.

Note: In all the options square of $\dfrac{17}{2}$ is missing in restricted domain.

7 0

3 years ago

2. What is the domain and range of the

Lapatulllka [165]

Answer:

domain: x ≥ 0
range: y ≥ 0

Step-by-step explanation:

The domain of a function is the set of x-values for which it is defined. The range of a function is the set of y-values the function produces.

<h3>Domain</h3>

The domain is the horizontal extent of the graph. This graph extends from x=0 toward x→∞. The domain is x ≥ 0. In interval notation, it is written [0, ∞).

<h3>Range</h3>

The range is the vertical extent of the graph. This graph extends from y=0 toward y→∞. The range is y ≥ 0. In interval notation, it is written [0, ∞).

6 0

2 years ago

Can someone please answer this and explain it?

professor190 [17]

Answer:

Velocity = displacement / time

Distance = 3t^2 +2t +6 to find distance you need to plug in time = 2 sec

Distance = 3(2)^2 +2(2) +6

Distance = 3(4) +4 + 6

Distance = 12 + 4 +6

Distance = 22 meters

In this problem the displacement is the distance.

Velocity = 22 meters / 2 second

Velocity = 11 meters/second

Does this help?

Step-by-step explanation:

4 0

3 years ago