Question

10+-2f^2+-6+7+-2f^2+-9f

Answer 1

$10+(-2f^{2})+(-6)+7+(-2f^{2})+(-9f)=10-2f^2+1-2f^2-9f$

$-4f^2-9f+11=-(4f^2+9f-11)$

Answer 2

$10+-2f^2+-6+7+-2f^2+-9f = 10-2f^2 -6+7-2f^2 -9f \\\\= -2f^2 -2f^2 -9f+10-6+7= \boxed {-4f^2 -9f +11}$