solve (x+3)(x+6)=4

Question

I have to solve (x+3)(x+6)=4 setting the equation to zero.  Im not sure what to do once I move the 4 to the left to make it (x+3)(x+6)-4=0

Answer 1

First try FOILing the two sets of parentheses:

(x+3)(x+6)-4=0

x² + 3x + 6x + 18 - 4 = 0

x² + 9x + 14 = 0

Now do you know how to factor this? Look for two numbers that multiply to equal 14, and add up to 9, then you can put the factors into the parentheses:

(x + _)(x + _) = 0