Question

Factor the expression below.

x² + 18x+81
OA. (x-9)(x-9)
B. (x3)(x-27)
O C. (x+9)(x + 9)
OD. (x+3)(x+27)

Answer 1

C)
`(x+9)(x+9)`

Explanation:

`x^2+18x+81\\x^2+9x+9x+81\\x(x+9)+9(x+9)\\(x+9)(x+9)`

Answer 2

Answer: C. (x + 9)(x + 9)

Explanation:

To factor the given expression, we need to find two terms that will equal the expression when added together.

To do this with a quadradic equation that doesn't have a coefficient, we will find two numbers that add to b and multiply to c (ax² + bx + c)

9 and 9 will add to 18 and multiply to 81. These are our factors.

To write this as factored form, we write:

(x + 9)(x + 9)

This works because when you multiply it out, you get an x², two 9xs (add together to 18x), and an 81.