Question

Question #8c1e4

Answer 1

`x=3` and `y=1`

Explanation:

`-3x+2y=-7`
`3x+3y=12`

From the first equation, derive a value for `3x`.

`-3x+2y=-7`

Multiply all terms with `-1`.

`3x-2y=7`

Add `2y` to both sides.

`3x=7+2y`

In the second equation, substitute `3x` with `color(red)((7+2y))`.

`3x+3y=12`

`color(red)((7+2y))+3y=12`

Open the brackets and simplify.

`color(red)(7+2y)+3y=12`

`7+5y=12`

Subtract `7` from each side.

`5y=5`

Divide both sides by `5`.

`y=1`

In the second equation, substitute `y` with `color(blue)(1)`.

`3x+3y=12`

`3x+3color(blue)((1))=12`

Open the brackets and simplify.

`3x+3=12`

Subtract `3` from each side.

`3x=9`

Divide both sides by `3`.

`x=3`