Answer:
4 was multiplied by 3; instead the 4 should've been raised by the power of 3.
Explanation:
For my analysis I am assuming that the exponent on the first figure is only on the variable.
(4x^3 y^7)^3
Distribute the exponent on the parentheses to all exponents inside of the parenthesis.
((4^3) ((x^3)^3) ((y^7)^3))
64(x^9)(y^21)
The error in the problem therefore, is that 4 was multiplied by 3 instead of raised by the power of 3 (4(4)(4)).