Question

How do you factor 2x^2-8?

Answer 1

first factor out the GCF 2

2x^2 - 8 = 2(x^2 - 4)

Answer 2

what's your next step?

Answer 3

i have no idea! i don't know how to factor these at all!

Answer 4

are you familiar with the difference of squares rule?

Answer 5

no, i am studying for a placement test. so, most of the problems i have never learned anything about.

Answer 6

it's the idea that

a^2 - b^2

factors to

(a-b)(a+b)

Answer 7

so x^2 - 4 can be written as x^2 - 2^2

Answer 8

then you can see that a = x and b = 2

Answer 9

so what does that mean in this case?

Answer 10

sorry, i'm lost

Answer 11

x^2 - 4 can be written as x^2 - 2^2

does that make sense?

Answer 12

i found it in my husband's old college algebra book, so i am gonna look it over now. thank you for your help ;)

Answer 13

alright, anyways you would factor x^2 - 4 to get (x-2)(x+2) using the difference of squares rule above

Answer 14

so

2(x^2 - 4)

turns into

2(x-2)(x+2)

Answer 15

I think I got it!
50-2x^2=2(5-x)(5+x)
:)

Answer 16

that was actually really easy! thank you for your help jim_thompson5910 :)