I am confused on these problems:

the measure of the complement of an angle is fifteen less than four times the measure of the angle. Find the measure of the angle and its complement.

The baseball company manufactures two grades of baseballs, the speedee, which sells for $2.10, and the Quickfire, which sells for $3.50. The company receives $843.50 for an order of 305 balls. How many of each ball were ordered?

Value Hardware sells 3-in. finishing nails for 0.99/lb, and 2-in. finishing nails sell for 1.39/lb. Tony needs 5 lbs. of nails. If his bill totals $6.15, how many pounds of each size did he buy?

y varies directly as x^2

If y=4 when x=6, find y when x=9.

If y=16 when x=4, find x when y=25