Chapter 7 - Exponents and Exponential Functions - 7-2 Multiplying Powers With the Same Base - Practice and Problem-Solving Exercises - Page 430: 30

The answer is 400rs

To solve this (4$r^{\frac{2}{5}}$$\times$5$s^{\frac{2}{7}}$)($5s^{\frac{5}{7}}$$\times$4$r^{\frac{3}{5}}$) = (4$\times$4)($r^{\frac{2}{5}+\frac{3}{5}}$)(5$\times$5)($s^{\frac{2}{7}+\frac{5}{7}}$) = (16$r^{\frac{5}{5}}$)(25$s^{\frac{7}{7}}$) = 400$\times$$r^{1}$$\times$$s^{1}$ = 400rs