Question

Please answer 5,6,7. With explanation.

Answer 1

First you need to know some rules 2 numbers that are the same with coefficients divided : you differentiate those coeff
and multyplied :you sum up them

12x^8/3x^3= 4x^8-3=4x^5

20^2x=20^x*20^x

m^5*m^-7=m^5-7=m^-2