#### Answer

The answer is $54 x^{7}y^{15}$.

#### Work Step by Step

The given expression is
$(2x^4y^3)(3xy^4)^3$
Multiply the power of the bracket with power of terms inside the bracket.
$(2x^4y^3)(3^3x^3y^{12})$
Clear the parentheses and add powers of the like terms.
$2\cdot3^3\cdot x^{4+3}y^{3+12}$
Simplify.
$54 x^{7}y^{15}$.