Question

F(x) =-x^2+x+13
find f(9)

Answer 1

-59

Explanation:

f(x) =-x^2+x+13

Let x = 9

f(9) = - (9)^2 +9+13

= -81 +9+13

= -59

Answer 2

f(9) = - 59

Explanation:

Substitute x = 9 into f(x) , that is

f(9) = - (9)² + 9 + 13

= - 81 + 22

= - 59