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2 years ago

Which of the following (x,y) pairs is the solution for the system of equations x+2y=4 and -2x+y=7

Mathematics

1 answer:

kakasveta [241]2 years ago

3 0

Answer:

(-2 ,3)

Step-by-step explanation:

Step 1: Rewrite first equation

x = 4 - 2y

-2x + y = 7

Step 2: Substitution

-2(4 - 2y) + y = 7

Step 3: Solve y

-8 + 4y + y = 7

-8 + 5y = 7

5y = 15

y = 3

Step 3: Plug in y to find x

x + 2(3) = 4

x + 6 = 4

x = -2

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OlgaM077 [116]

Answer:

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Step-by-step explanation:

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2 years ago

two point on a line are (-10,1) and (5,-5). if the y-coordinate of another pinot on the line is -3, what is the x_coordinate?

Bezzdna [24]

Using the two points we can find the slope of the line using (y2-y1)/(x2-x1):
(-5-1)/(5-(-10))=-6/15=-3/5. Then we can use the formula y-y1=m(x-x1). Out of the 5 variables, we have 4 of them: y=-3, y1=1, m=-3/5, and x1=-10. Now we just solve for x: -3-1=(-3/5)(x-(-10)).
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20/3-10=x, so the x coordinate is -10/3.

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2 years ago