13. Luyin's demand for tangerines is D (p,m) = 4-2p +m/10, where p is the price of tangerines and m is her income. if p=1 and m=100, what is her

13. Luyin's demand for tangerines is D (p,m) = 4-2p +m/10, where p is the price of tangerines and m is her income. if p=1 and m=100, what is her income elasticity of demand?

14. Amir's inverse demand for cheese is given by p=4 -q/5 and Azam's inverse demand for cheese is p =4-q/10. What price will maximize the total revenue generated from selling cheese to these two consumers?

I know what the answers to these questions are but I don't know how to solve it....please show me how you came to you answer!