Question

How do you solve the following system: `x-2y=4, 2x-y=7`?

Answer 1

`(x, y) = (10/3, -1/3)`

Explanation:

First, define one variable (let's do x) in terms of the other (y). Using the first equation, we can conclude that `x=2y+4`. Then, we can substitute `2y+4` into anywhere we see x in the second equation, so:
`2(2y+4) - y = 7`
`4y+8-y=7`
`3y+8=7`
`3y=-1`
`y=-1/3`
Then, plug y back into the first equation to find x.
`x-2(-1/3) = 4`
`x+2/3 = 4`
`x = 10/3`