How do you solve the system #2x + y = 1 # and #4x + 2y = −1# by substitution?

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Answer 1 · 2015-05-31T22:27:39

We have the following system :

#2x+y=1#
#4x+2y=-1#

We need to isolate #x# or #y# on one of the equations. Let's isolate #y# on the first one, it's the easiest :

#2x+y = 1 hArr y = 1-2x#

Now we can replace the #y# on the second equation :

#4x+2y=4x+2(1-2x)=4x-4x+2=2 != -1#.

There aren't any solutions to that system.