2 x + 3*x - 7
x^2 + 3*x - 7
2 -7 + x + 3*x
-7 + x^2 + 3*x
/ ____\ / ____\ | 3 \/ 37 | | 3 \/ 37 | |x + - - ------|*|x + - + ------| \ 2 2 / \ 2 2 /
(x + 3/2 - sqrt(37)/2)*(x + 3/2 + sqrt(37)/2)
-7.0 + x^2 + 3.0*x
-7 + x*(3 + x)