Question

How do you solve `m( m + 8) = - 7`?

Answer 1

`color(blue)(m=-1)` or `color(blue)(m=-7)`

Explanation:

If
`color(white)("XXX")m(m+8)=-7`
then
`color(white)("XXX")m^2+8m=-7`

`color(white)("XXX")m^2+8m+7=0`

`color(white)("XXX")(m+1)(m+7)=0`

`rarr color(white)("xxx")(m+1)=0color(white)("xxxxx")"or"color(white)("xxx")(m+7)=0`
`color(white)("xxxxxx")rarr m=-1color(white)("xxxxx")"or"color(white)("xxx")rarr x=-7`