How do you solve the system of equations #4x - 2y = - 2# and #x + 2y = - 13#?

1 Answer
Jun 23, 2017

#x=-3#

#y=-5#

Explanation:

Solve system of equations:

#color(red)(4x-2y=-2# and #color(blue)(x+2y=-13#

We need to solve one equation for either #x# or #y#. Then substitute that result into the other equation, replacing either #x# or #y#. Once we have a numerical value for #x# or #y#, substitute it into the other equation to solve for #x# or #y#.

I'm going to start with #color(blue)(x+2y=-13# and solve for #x#.

Subtract #2y# from both sides.

#x=-2y-13#

Now substitute this value for #x# into the other equation: #color(red)(4x-2y=-2#.

#4(-2y-13)-2y=-2#

Expand.

#-8y-52-2y=-2#

Add #52# to both sides.

#-8y-2y=-2+52#

Simplify.

#-10y=50#

Divide both sides by #-10#.

#y=-50/10#

Reduce the fraction.

#y=-5#

Now substitute the value for #y# into the previous equation: #color(blue)(x+2y=-13#.

#x+(2)(-5)=-13#

Simplify.

#x-10=-13#

Add #10# to both sides.

#x+-13+10#

Simplify.

#x=-3#