How do you solve for the x if 8x=y8x=y and 2x+y=52x+y=5?

1 Answer
May 23, 2018

Substitute out yy in the second equation and solve for xx, which is x=0.5x=0.5

Explanation:

The first expression gives us a solution for yy in terms of xx:

color(blue)(8x=y)8x=y

We can take this solution and substitute all values of yy in equation 2:

2x+color(blue)y=52x+y=5

2x+color(blue)(8x)=52x+8x=5

Because we know color(blue)(y=8x)y=8x we can make this substitution. Now all that's left is to solve for xx

10x=510x=5

(cancel(10)x)/color(red)(cancel(10))=5/color(red)(10)

color(green)(x=1/2=0.5)