How do you solve x + y = 1 and 3x – y = 11?

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Answer 1 · 2018-04-11T21:53:08

#y=-2# and #x=3#.

You need to use simultaneous equations. Make #x# or #y# the subject from one equation and substitute it into the other.

#x=1-y#

Then

#3(1-y)-y=11#

#3-3y-y=11#

#3-4y=11#

#4y=-8#

#y=-2#

If #y=-2#, substitute back into either equation to find #x#.

#x-2=1#

#x=3#