помогите, пожалуйста, с заданием ​

21.

в)

f (х) = (х² - 9)/(х + 3),

f (-2) = ((-2)² - 9) / (-2 + 3) = (4 - 9) / 1 = -5,

f (1/3) = ((1/3)² - 9) / (1/3 + 3) = (1/9 - 81/9) / (1/3 + 9/3) =

          = -80/9 : 10/3 = -80/9 * 3/10 = -8/3 = - 2 2/3,

г)

f (х) = 1/х²,

f (-2) = 1 / (-2)² = 1/4,

f (1/3) = 1 / (1/3)² = 1 : 1/9 = 1 * 9 = 9