Question

Question #4e3ef

Answer 1

`x=7`, `y=-16`

Explanation:

`color(white)(-)x+y=-9`
`color(white)(-)`
`x+2y=-25`

Let's use elimination here. We can subtract both equations to remove the `x`:
`color(white)(-)cancel(x)+y=-9`
`color(black)(-)`
`cancel(x)+2y=-25`
.......................................
`-y=16`
`y=-16`

Now let's solve for `x` by replacing `y` with `-160.`
`x+y=-9`
`x+(-16)=-9`
Add `16` on both sides
`x=7`

Just to double check our work, we'll solve the second problem using `7` and `-16` for `x` and `y`, respectively.
`x+2y=-25`
`7+ 2*(-16)` should equal `-25`
`7-32=12`
`12=12`
We were right! Good job!

Answer 2

`color(blue)(x=7`

Explanation:

`x+y=-9-----(1)`

`x+2y=-25-----(2)`

`(1) xx 2` `2x+2y=-18----(3)`

`(2)-(3)` `-x=-7`

`color(blue)(x=7`

sustitute `x=7` in `(2)`

`7+2y=-25`

`2y=-25-7`

`2y=-32`

`y=-32/2`

`y=-16`

Check:

substitute `color(blue)(x=7` and `color(blue)(y=-16` in `(1)`

`color(blue)7+(color(blue)-16)=-9`

`-9=-9`