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Question

mudkillz · Answer

Factor completely: 3a2 + 5a − 12
A  Prime
B (3a + 4)(a − 3)
C (3a − 4)(a + 3)
D (3a − 3)(a + 4)

daniellelovee · Answer

you can distributive property on each to see if they equal, or you can factor it

mudkillz · Answer

I'm trying to factor, but I can never get it quite right

daniellelovee · Answer

3a2+9a−4a−12
Factor out common terms in the first two terms, then in the last two terms
3a(a+3)−4(a+3)
Factor out the common term a+3

mudkillz · Answer

where did you get 9a and -4a?

daniellelovee · Answer

Multiply 3 by -12, which is -36.
2. Ask: Which two numbers add up to 5 and multiply to -36?
3. Answer: 9 and -4
4. Rewrite 5a5a as the sum of 9a9a and −4a−4a:

mudkillz · Answer

Okay, I see. I did some math on my side, and (3a-4)(a+3) is the right answer. Thanks for your help! finally understood how to factor that!

daniellelovee · Answer

yes you are correct and sorry I took long but my computer started typing in japanese so now I have to fix that