Question

How do you solve the following linear system: `3x + 5y = -1, 3x+y=-2`?

Answer 1

`(x,y)=(-3/4,1/4)`

Explanation:

Given:
[1]`color(white)("XXX")3x+5y=-1`
[2]`color(white)("XXX")3x+y=-2`

Subtract [2] from [1]
[3]`color(white)("XXX")4y = 1`
Divide [3] by 4
[4]`color(white)("XXX")y = 1/4`

Substitute `1/4` for `y` in [2]
[5]#color(white)("XXX")3x+1/4 =-2 Subtract #1/4# from both sides of [5] [6]#color(white)("XXX")3x = -9/4# Divide [6] by #3# [7]#color(white)("XXX")x = -3/4#