Question 424823
x2+7x+12=0

x^(2)+7x+12=0

For a polynomial of the form x^(2)+bx+c, find two factors of c (12) that add up to b (7).  In this problem 4*3=12 and 4+3=7, so insert 4 as the right hand term of one factor and 3 as the right-hand term of the other factor.
(x+4)(x+3)=0

Set each of the factors of the left-hand side of the equation equal to 0.
x+4=0_x+3=0

Since 4 does not contain the variable to solve for, move it to the right-hand side of the equation by subtracting 4 from both sides.
x=-4_x+3=0

Set each of the factors of the left-hand side of the equation equal to 0.
x=-4_x+3=0

Since 3 does not contain the variable to solve for, move it to the right-hand side of the equation by subtracting 3 from both sides.
x=-4_x=-3

The complete solution is the set of the individual solutions.
x=-4,-3