How do you solve y= -2x + 2 and 6x + 2y = 3?

1 Answer
Jun 18, 2018

(x,y)=(-1/2,3)(x,y)=(12,3)

Explanation:

Given
[1]color(white)("XXX")y=-2x+2XXXy=2x+2
[2]color(white)("XXX")6x+2y=3XXX6x+2y=3

The form given for equation [1] makes solution by substitution the most obvious method:

Base on [1] we can substitute (-2x+2)(2x+2) for yy in [2]
[3]color(white)("XXX")6x+2(-2x+2)=3XXX6x+2(2x+2)=3

Simplifying [3]
[4]color(white)("XXX")2x+4=3XXX2x+4=3
or
[5]color(white)("XXX")x=-1/2XXXx=12

We can now substitute (-1/2)(12) for xx in [1]
[6]color(white)("XXX")y=-2(-1/2)+2=3XXXy=2(12)+2=3