Question

Factor completely.
-3x² + 6x + 9 =

Answer 1

-3(x - 3) (x + 1)

Explanation:

Let's check

-3(x - 3) (x + 1)

(-3x + 9) (x + 1)

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

-3
`x^(2)` + 6x + 9

Answer 2

-3(x-3)(x+1)

Explanation:

A common factor that all three numbers share is that they are divisible by 3, so we can factor 3 out. Typically, I take out the negative first:

-3(
`x^2-2x-3`) (always remember to change signs!)

Now, we are left with
`x^2-2x-3`, and to factor that out, we need to find two numbers that add up to -2 and multiply to -3. These two numbers will be 1 and -3, so we can write our factor like this:

(x-3)(x+1)

Let's add back in the -3 from earlier to complete our factoring:

-3(x-3)(x+1)