How do you solve the following system: 2x - 3y = 10 , 2x + 3y = 12?

1 Answer
Dec 14, 2015

color(white)(xx)x=11/2, and y=1/3

Explanation:

color(white)(xx)2x-3y=10,color(white)(x)2x+3y=12

color(white)(xx)2x-3y=10<=>3y=2x-10
color(white)(xx)2x+3y=12<=>3y=-2x+12

=>2x-10=y
=>2x-10=color(red)(-2x+12)

Add color(red)(+2x+10) to both side:
color(white)(xx)2x-10color(red)(+2x+10)=-2x+12color(red)(+2x+10)
=>4x=22

Multiply both sides by color(red)(1/4):
color(white)(xx)color(red)(1/4xx)4x=color(red)(1/4xx)22
=>x=11/2

color(white)(xx)3y=2x-10
=>3y=2xxcolor(red)(11/2)-10
=>3y=1

=>color(red)(1/3xx)3y=color(red)(1/3xx)1
=>y=1/3