Question

Factor the expression below.

x^2 - 8x + 16

Answer 1

A. 4(x2 - 2x + 4)
B. (x - 4)(x + 4)
C. (x - 4)(x - 4)
D. (x + 4)(x + 4)

Answer 2

i think it is B?

Answer 3

So what are the factors?

Answer 4

-4 and +4

Answer 5

-4 times 4 is NOT 16 and -4+4 is NOT -8

Answer 6

sorry im not smart i dont understand this

Answer 7

You do know FOIL though. So you need to fill in the right numbers so that when you multiply (x )(x ) you will get x^2-8x + 16

Answer 8

yes

Answer 9

And after we do it for a few times we realize that the right numbers are the ones whose product is 16 and whose sum is -8

Answer 10

And we know that -4(-4)=16 and -4+-4=-8

Answer 11

So we fill in the blanks in the two binomials with -4 and -4 and we get:
x^2-8x+16=(x-4)(x-4)

Answer 12

And then we FOIL it to make sure we have the right factors.

Answer 13

Its just like if you tell me that the factors of 12 are 4 and 3, I will quickly multiply 4 times 3 to verify you are right.

Answer 14

ok

Answer 15

Do you have a question?

Answer 16

no

Answer 17

Good