Question

Factor: x2 - 9x + 12

Answer 1

Well, the outer terms have to equal 12. The inner terms have to add to equal -9.

What options do you have?

Answer 2

A. (x + 1)(x - 12)
B. (x + 2)(x + 6)
C. (x - 2)(x - 6)
D. prime

Answer 3

It's prime. None of the other options produce -9x when the inside and outside terms are added together.... Does that make sense to you?

Answer 4

yes, thank you (:

Answer 5

\[(x + 1)(x - 12)=x^2-11x-12\neq x^2 - 9x + 12\]
\[(x + 2)(x + 6)=x^2+8x+12\neq x^2 - 9x + 12\]
\[(x - 2)(x - 6)=x^2-8x+12\neq x^2 - 9x + 12\]

Answer 6

\[x=\frac{-b^2\pm \sqrt{b^2-4ac}}{2a}\]a=1, b= -9 , c=12