What are x and y if x+y=4 and y=-7x+4?

1 Answer
Apr 11, 2018

Please look below.

Explanation:

x + y = 4 ---(1)

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

The x s and y s in the question are of the same value. This means that you can substitute the value of y in the second equation into the first equation:

x + (-7x +4) = 4

This allows you to find x:

x-7x + 4 = 4

-6x = 0

x = 0

Then this value can be substituted into either of the given equations:

0 + y = 4

y = 4

So x = 0 and y = 4.