Question

Factor x2 - 8x + 9
Answer

(x + 9)(x - 1)

(x + 9)(x + 1)

(x - 9)(x - 1)

Prime

Answer 1

Find two numbers that multiply to 9 and add to -8 at the same time

Answer 2

take the 9 and write down all the factors. one of those pairs will add to give -8.

consider all the possibilities: remember only some of these give +9 and -8

+1x+9
+3x+3

which of these would make -8 by a change of sign

Answer 3

Actually none of the answers given solve the eqn. as far as I can see

Answer 4

are you sure its not \[x^2+8x-9\]

Answer 5

kevsturge if it doesn't factor, then it's prime

Answer 6

Ah, prime means it doesn't factor. didn't know that, thanks