how to work this problem by factoring then solving

Question

x²+6x+8=0

Answer 1

8 can be factored 2 ways: 4x2 or 8x1.  Combining 8+1 = 9 does not equal the 6x you need.  Therefore, we'll have to use the 4 and 2 factors.

You'll factor by:
(x+4)(x+2) = 0    (Check by FOILING: x² (First) + 2x (Outer) + 4x (Inner) + 8 (Last) = x² + 6x + 8)

 

(x+4) = 0             or (x+2) = 0

x + 4 = 0                  x + 2 = 0

x = -4                        x = -2