Question

How do you solve the system of equations `3x - 9y = 0` and `8x - 2y = 66`?

Answer 1

`x=9` and `y=3`

Explanation:

`3x-9y=0`
`8x-2y=66`

Reduce the first equation to get a value for `x`.

`3x-9y=0`

Add `9y` to both sides.

`3x=9y`

Divide all terms by `3`.

`x=3y`

In the second equation, substitute `x` with `color(red)3y`.

`8x-2y=66`

`8(color(red)3y)-2y=66`

Open the brackets and simplify.

`24y-2y=66`

`22y=66`

Divide both sides by `22`.

`y=3`

In the first equation, substitute `y` with `color(blue)3`.

`3x-9y=0`

`3x-9(color(blue)3)=0`

Open the brackets and simplify.

`3x-27=0`

Add `27` to both sides.

`3x=27`

Divide both sides by `3`.

`x=9`