Question

How do you solve the following system?: `x +2y = 7 , 2x - 7y = 1`

Answer 1

`(x,y)=(51/11,13/11)`

Explanation:

`x=7-2y` solve for `x` in terms of `y` using the first equation
`2(7-2y)-7y=1` plug into the other equation
`14-4y-7y=1` distribute
`14-11y=1` combine
`-11y=-13`
`y=13/11`

Now, going back to the other equation (the first one)
`x+2(13/11)=7` plug in value of `y`
`x+26/11=7`

`x+26/11=77/11`

`x=51/11`