The formula for the bowline of a sphere is v=4/3πr^3. solve for r

Acontractor needs 54 square feet of brick to construct a rectangular walkway. the length of the walkway is 15 feet more than the width. write an equation that could be used to determine the dimensions of the walkway. solve this equation to find the length and width, in feet, of the walkway.

The cash price of a television is $580.the hire-purchase price of the television is $865.the hire-purchase price is an initial deposit of n% of the cash price and 6 equal monthly payments of $120.find the value of n.

Two customers went to a post office. first customer paid $12 for 14 and 5 envelopes the second paid 24.80 for 10 postcards and 15 envelopes. what is cost of each envelope?