How do you solve the following system using substitution?: -3x + 3y= 3, -5x + y = 133x+3y=3,5x+y=13

1 Answer
Oct 26, 2015

x=-3x=3
y=-2y=2

Explanation:

First, isolate yy in the first equation.

color(blue)([1])" "-3x+3y=3[1] 3x+3y=3

color(blue)([2])" "3y=3+3x[2] 3y=3+3x

color(blue)([3])" "y=1+x[3] y=1+x

Now substitute the value of yy in the first equation to yy in the second equation.

color(red)([1])" "-5x+color(blue)(y)=13[1] 5x+y=13

color(red)([2])" "-5x+color(blue)((1+x))=13[2] 5x+(1+x)=13

color(red)([3])" "-4x=12[3] 4x=12

color(red)([4])" "x=-3[4] x=3

Now that we have the value of xx, we will simply substitute this to the first equation.

color(blue)([4])" "y=1+(-3)[4] y=1+(3)

color(blue)([5])" "y=-2[5] y=2