How do you solve the following linear system: # x+y+1 , 2x+y=7 #?

1 Answer
Nov 25, 2015

The simplest way would be to subtract the first equation from the second

Explanation:

#2x+y=7#
#-(x+y=1)# and you will get:
#(2x-x)+(y-y)=(7-1)->x=6#

If you substitute this in one of the equations:
#x+y=1->6+y=1->y=-5#

Check with the other equation (just to make sure):
#2x+y=2*6+(-5)=7# check!