To find f(-20), first figure out which piece x = -20 fits with.
Since -20 < -12, x = -20 first in the domain used by the third piece.
For f(-20), treat this function as if it was just f(x) = 3x-7.
f(-20) = 3(-20) -7
= -60 - 7
= -67
Just multiply the sum of the numbers then divide
Let x = Barbie's number
1/3 x -20 = 72
1/3 x = 92
x = 92*3=276
Answer:
Step-by-step explanation:
