2 - x - 7*x + 9
-x^2 - 7*x + 9
2 9 - x - 7*x
9 - x^2 - 7*x
/ ____\ / ____\ | 7 \/ 85 | | 7 \/ 85 | |x + - - ------|*|x + - + ------| \ 2 2 / \ 2 2 /
(x + 7/2 - sqrt(85)/2)*(x + 7/2 + sqrt(85)/2)
9.0 - x^2 - 7.0*x
9 + x*(-7 - x)