Respuesta :

Answer:

21.

Step-by-step explanation:

f(4) is the value of f(x) when x = 4 so the answer is:

4^2 + 2*4 - 3

= 16 + 8 - 3

=  21.

Answer:

f(x)=21

Step-by-step explanation:

So the equation sad that the f(x) is equal to 4. Means the x is equal to 4.

If you plug in 4:

x^2+2x-3

4^(2)+2(4)-3

16+8-3

=21

The answer is 21.