Question

3r − 9 = –6r
solve for r

Answer 1

`\boxed {r = 1}`

Explanation:

Solve for the value of
`r`:

`3r - 9 = -6r`

-Add
`6r` to
`3r`:

`3r - 9 + 6r = -6r + 6r`

`9r - 9 = 0`

-Add
`9` on both sides:

`9r - 9 + 9 = 0 + 9`

`9r = 9`

-Divide both sides by
`9`:

`(9r)/(9) = (9)/(9)`

`\boxed {r = 1}`

So, the value of
`r` is
`1`.

Answer 2

3r − 9 = –6r

-9 = -6r-3r (you change the signs when bringing +3r to the other side)

-9 = -9r

r = -9/-9

r = 1