factor completely

(x+9)^2 -5(x+9)-6

how do i do this one?

Pretend it is

u^2-5u-6

factor, then substitue back in.

how about letting x+9 equal y, then your expression is

y^2 - 5y - 6

now it is easy to see the factors, once done replace y with x+9

let me know what you got

x+9=y

y^2-5y-6

(y-3)(y+2)

(x+9-3)(x+9+2)

is this it or close?

To factor the expression completely, you can use a method called grouping. Here's how you can do it step by step:

Step 1: Rewrite the expression in the form of a quadratic equation by grouping the terms with the common factor.
(x+9)^2 -5(x+9)-6
= [(x+9)^2 -5(x+9)] - 6

Step 2: Factor out the common terms from the first two terms in the parentheses.
= [(x+9)(x+9) - 5(x+9)] - 6

Step 3: Notice that both terms inside the brackets have a common factor of (x+9). Factor it out.
= (x+9)(x+9 - 5) - 6

Step 4: Simplify the expression inside the brackets.
= (x+9)(x+4) - 6

So, the factored form of the expression is (x+9)(x+4) - 6.