6r^5 s^3 * 3r^2 s^6. Please help

6r^5 s^3 * 3r^2 s^6   we can write this as

6 * 3 * r^5 * r^2 * s^3 * s^6  =        [using a^m * aⁿ  = a^{m + n} ] 

18 * r^7 * s^9