Question

How do you find the point of intersection for `3x-y=1` and `x+y=3`?

Answer 1

`(x,y) = (1,2)`

Explanation:

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

Add [1] and [2]
[3]`color(white)("XXXX")` `4x = 4`

Divide both sides of [3] by 4
[4]`color(white)("XXXX")` `x = 1`

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

Subtract `1` from both sides of [5]
[6]`color(white)("XXXX")` `y = 2`