How do you solve X for the following equations #2x+5y=10, y=-x-1#?

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Answer 1 · 2016-11-29T06:10:05

#x=-5#

#2x+5y=10#
#y=-x-1#

In the first equation, substitute #y# with #(-x-1)#.

#2x+5(-x-1)=10#

Open the brackets. The multiplication of negative positive yields a negative.

#2x-5x-5=10#

#-3x-5=10#

Add #5# to each side.

#-3x=15#

Divide each side by #3#.

#-x=5# or #x=-5#