Answer
(r+9)(r-3)
Work Step by Step
Given the polynomial
$r^{2}$ + 6r - 27
*** We break of the middle term into two factors that add to give +6 and multiply to give -27. The two numbers are +9 and -3.
$r^{2}$ + 9r - 3r - 27
We take the GCD of the first two and the GDC of the last two terms.
r(r+9) -3(r+9)
We take (r+9) and factor it out which gives us.
(r+9)(r-3)