How do you find the point of intersection for x+3y=12 and x-y=4?

1 Answer
Jul 1, 2015

The point of intersection occurs at (x,y) = (6,2)

Explanation:

[1]color(white)("XXXX")x+3y=12
[2]color(white)("XXXX")x-y = 4

Subtract [2] from [1] to remove the variable x from the equation
[3]color(white)("XXXX")4y = 8#

Divide both sides of [3] by 4
[4]color(white)("XXXX")y = 2

Substitute y=2 in [1]
[5]color(white)("XXXX")x+3(2) = 12

Simplifying
[6]color(white)("XXXX")x = 6