Question

How do you solve the simultaneous equations `3x+y=1` and `x-2y=19`?

Answer 1

`(x,y) \in {(3,-8)}`

Explanation:

`y = 1 - 3x`

`x - 2(1 - 3x) = 19`

`x - 2 + 6x = 19`

`7x = 21`

`x = 3`

`y = 1 - 3 \cdot 3`