Express in terms of "z" : 1/y- 1/z= 1/x

What is the simplified form of 7 √x • 7 √x • 7 √x • 7 √x?

Avegetable garden and a surrounding path are shaped like a square together are 12 ft wide. the path is 1 feet wide. if one bag of gravel covers 8 square feet, how manu bags are needed to cover the path? round your answers to the nearest tenth.

(! ) three cylinders have a height of 8 cm. cylinder 1 has a radius of 1 cm. cylinder 2 has a radius of 2 cm. cylinder 3 has a radius of 3 cm. find the volume of each cylinder