Respuesta :

Answer:

-196

Step-by-step explanation:

f(x) = (7-x)^2

     plug in the value of x

f(x) = (7-21)^2

      subtract 7 from 21

f(x) = (-14)^2

      now take -14 to the 2nd power

f(x) = -196

      your answer would be -196

Answer:-28

Here x would be 21 so you fill in 21 for x.

f(21)=(7-21)2

Then you would subtract 21 from 7, leaving you with -14. You do this because you have to follow BEDMAS (brackets, exponents, division, multiplication, addition, subtraction).

f(21)=(-14)2

Lastly, you multiply the -14 by 2 because you have to get it out of the brackets. So you would be left with f(21)=-28

f(21)=-28

Step-by-step explanation: