solve ^4√x^3 =8

^4√x^3 =8

^4√x^3 =2^3 (<--- change the right hand side "8" into the same base as the left hand side first, that is "2")

therefore, ^4√x =2

x=2^4=16

solve
-^4√x^3 =8

- x^3=8^4
- x=^3√4096
- =16