Respuesta :

Answer:

Step by step solution : Step 1 :Trying to factor by splitting the middle term. 1.1 Factoring x2-5x-24

Step-by-step explanation:

Answer:-21

Step-by-step explanation:f(x)=−x

2

+5x+15

Find

f

(

9

)

Find f(9)

(

9

)

2

+

5

(

9

)

+

15

−(9)

2

+5(9)+15

Plug into each x-value

(

81

)

+

5

(

9

)

+

15

−(81)+5(9)+15

Square first

81

+

45

+

15

−81+45+15

Multiply and negate

f

(

9

)

=

21

f(9)=−21