What is the index form of 4x4x7x7x7?

The index form of 4x4x7x7x7 is 4^2 x 7^3. This is because 4 is raised to the power of 2 (since there are two occurrences of 4) and 7 is raised to the power of 3 (since there are three occurrences of 7). So, the index form simplifies the expression by showing the bases and their respective exponents.