Question

4x – 2y = –1 3 and –4x + 4y = –2 what does x and y equal?

Answer 1

The solution is (-7, -7 1/2)

Explanation:

4x – 2y = –13

–4x + 4y = –2

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2y = -15, and so y = -7 1/2.

Now find x. If y = -7 1/2, then, from the first equation, we get

4x - 2(-7 1/2) = -13, or

4x + 15 = -13, or

4x = -28, or x = -7

The solution is (-7, -7 1/2).

Answer 2

X = -7 and y = -7.5

Explanation:

Use substitution. Let’s try to get x by itself in the second question since it seems easier.

-4x + 4y = -2

-4x = -2 -4y

x = 1/2 + y

Subsitute that into the other equation for y.

4x -2y = -13

4(1/2 + y) - 2y = -13

2 + 4y -2y = -13 # Use the distributive property

2y = -15 # put together like terms

y = -7.5

Then plug it into the x formula

x = .5 -7.5

x = -7