Answer:
[tex]\huge\boxed{r^2+6r-27=(r+9)(r-3)}[/tex]
Step-by-step explanation:
[tex]r^2+6r-27=r^2+9r-3r-27\\\\\text{use the distributive property:}\ a(b+c)=ab+ac\\\\=r(r+9)-3(r+9)\\\\\text{use the distributive property:}\ a(b+c)=ab+ac\\\\=r\underbrace{(r+9)}_{a}-3\underbrace{(r+9)}_{a}=(r+9)(r-3)[/tex]
