I'm assuming the two equations are as follows: y = 5x 7x + 2y = -17
You can substitute 5x for y in the second equation since they are equivalent. Remember that whatever you do to one side you must do to the other as well. 7x + 2y = -17 7x + 2(5x) = -17 7x + 10x = -17 17x = -17 17x /17 = -17 /17 x = -1
Now we sub in the value we have for x to find y: y = 5x y = 5(-1) y = -5
We now check that both answers are right by substituting them both into the second equation: 7x + 2y = -17 7(-1) + 2(-5) = -17 -7 + (-10) = -17 -17 = -17
And it looks like it works! So x = -1, and y = -5. Hope this helps! :)
