2 5*x - 4*x - 7
5*x^2 - 4*x - 7
/ ____\ / ____\ | 2 \/ 39 | | 2 \/ 39 | |x + - - + ------|*|x + - - - ------| \ 5 5 / \ 5 5 /
(x - 2/5 + sqrt(39)/5)*(x - 2/5 - sqrt(39)/5)
2 -7 - 4*x + 5*x
-7 - 4*x + 5*x^2
-7.0 + 5.0*x^2 - 4.0*x
-7 + x*(-4 + 5*x)