How do solve the following linear system?: 3x + 4y = -2 , x - 3y = 1 ?

1 Answer
May 25, 2016

x=-2
y=1

Explanation:

3x+4y=-2" (1)"
-2x-3y=1" (2)"

"expand both sides of equation (1) by 2;"
6x+8y=-4
"rearranging the equation :" 6x=-4-8y" "(3)

"expand both sides of equation 2 by 3;"
-6x-9y=3
"rearranging the equation :"6x=-9y-3" "(4)

"Both ;the left sides of equations (3) and (4) are equal"

color(red)(6x)=-4-8y
color(red)(6x)=-9y-3

"The right sides of equations can be written as equal"

-4-8y=-9y-3

9y-8y=-3+4

y=1

"now use (1) or (2)"

3x+4*1=-2
3x+4=-2
3x=-6
x=-6/3
x=-2