How do you solve the system of equations #2y = 10-7x# and #2x=20-2y#?

1 Answer
Nov 8, 2017

Answer:

Solve for #x#, then #y# using elimination.

#x = -2, y = 12#

Explanation:

First, move #x# and #y# to the same side of the equation so they are on top of each other. Make sure to watch your signs. Add #7x# to the top and add #2y# to the bottom.

#7x + 2y = 10#
#2x + 2y= 20#

Multiply bottom equation by #-1# to eliminate #y#.

#7x + 2y = 10#
#-2x - 2y = -20#

Add the bottom equation to the top. You're left with only #x#.

#5x = -10#

Solve for #x#, then plug #x# into either of the original equations to get #y#.

#x = -2, y = 12#