Question

How do you solve `3x + 4y = 7` and `5x - 2y = 16`?

Answer 1

I found:
`x=3`
`y=-1/2`

Explanation:

I would multiply the second equation by `2` and add the two equations (in columns):
`{3x+4y=7`
`{color(red)(10x-4y=32` adding:
`13x+0=39`
`x=39/13=3`
Substitute back this value of `x` into the first equation:
`3*3+4y=7`
`9+4y=7`
`4y=-2`
`y=-1/2`