1/3^4=1/81
The answer is 1/81.
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
Well since its specifically 1/6 what makes a whole? 1 does, So 6/6 would be one whole. Its literally 6 of 1/6 are in a whole.
Example: 1/6 2/6 3/6 4/6 5/6 6/6(<--- aka 1 whole)
The answer is .....................1600......
