How do you solve the system 5x-7y=-16 and 2x+8y=26?

1 Answer
May 3, 2018

1) 5x-7y=-16
2) 2x+8y=26

2x=26-8y | *1/2
x=13-4y

-7y=-16-5x
7y=16+5x
7y=16+5(13-4y)
7y=16+65-20y
7y+20y=16+65
27y=81 | * 1/27

y=3

x=13-4(3)
x=1

y=3 and x=1

Explanation:

You can solve this system by finding what one variable equals from one of the equations, then put this into the other equation.

I went to find y here in the start. Because I saw that locking x by itself would be fair enough. It gave a clean x=13-4y, instead of fractions or such.

I then put what x equals to into the other y equation. So that I can find the integer value of y without having any x variables. Which gave the result of y=3.

From there, we can place the y=3 into the other equation and find the x value, x=13-4(3) instead of x=13-4y. Which gave the result of x=1.

From that, we now know that:
y=3 and x=1