[tex] \bf \left( \cfrac{3x}{2} \right)^4\implies \left( \cfrac{(3x)^4}{2^4} \right)\implies \left( \cfrac{3^4x^4}{2^4} \right)\implies \cfrac{81x^4}{16} [/tex]
Simplify the expression by distributing the exponent of 4 to both 3, x and 2:
3 raised to the 4th power is 81, x raised to the fourth power is x^4 and 2 raised to the 4th power is 16.
So your answer is 81x^4/16.
:)))