1st?- cynthia paid $0.20 per hobby magazine at a tag sale. She bought half of all the magazines that were for sale and paid $10. How many magazines were there in all?

2nd?-in the first problem, the amount of money cynthia pays is a function of the number of magazines she bought.
a- write an equation that shows what cynthia pays dollars (d) for the number of magazines (m) shes buys.
b- make a function table with four (m,d) pairs of your choosing that satisfy the function.