2 2*x + 12*x + 15
2*x^2 + 12*x + 15
2 15 + 2*x + 12*x
15 + 2*x^2 + 12*x
/ ___\ / ___\ | \/ 6 | | \/ 6 | |x + 3 + -----|*|x + 3 - -----| \ 2 / \ 2 /
(x + 3 + sqrt(6)/2)*(x + 3 - sqrt(6)/2)
15 + 2*x*(6 + x)
15.0 + 2.0*x^2 + 12.0*x