I am working on x^2 + 7x + 12 = 0

Question

Step-by-step explanation would be greatly appreciated! 

Answer 1

Hi William;

For the FOIL...

FIRST must be (x)(x)=x²

OUTER and INNER must add-up to 7x.

LAST must be (4)(3) or (3)(4) or (2)(6) or (6)(2) or (12)(1) or (1)(12) and both numbers must be positive to result in positive 7x.

(x+4)(x+3)

Let's FOIL...

FIRST...(x)(x)=x²

OUTER...(x)(3)=3x

INNER...(4)(x)=4x

LAST...(4)(3)=12

x²+3x+4x+12=0

x²+7x+12=0

So...

(x+4)(x+3)=0

Either or both parenthetical equations must equal zero.

x+4=0

x=-4

x+3=0

x=-3