Question

How do you solve `3x+y=4` and `2x+y=1`?

Answer 1

`(3, -5)`

Explanation:

I used substitution.

Isolate `y` in one of the equations.
`3x+y=4`
`y=4-3x`

Substitute `y` in `2x+y=1` for `4-3x`.
`2x+(4-3x)=1`
`2x+4-3x=1`
`4-x=1`
`-x=-3`
`x=3`

Substitute `x` back into `y=4-3x` find the value of `y`.
`y=4-3(3)`
`y=4-9`
`y=-5`

Answer (Coordinate Form): `(3, -5)`