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

Question

1744 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2018-05-23T23:41:35

Substitute out #y# in the second equation and solve for #x#, which is #x=0.5#

The first expression gives us a solution for #y# in terms of #x#:

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

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

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

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

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

#10x=5#

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

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