Answer:
10
Step-by-step explanation:
y = 5x + 3
x = 5y + 3
5y + 3 = x
5y = x - 3
y = x/5 - 3/5
f^-1(x) = x/5 - 3/5
(2⁶)ˣ = 1
2⁶ˣ = 1
6x = 0
x = 0
216
LxWxH fill it in 3x6x12=216