Write the expression using exponents

Mary works for a company that ships packages and must measure the size of each box that needs to be shipped. mary measures a box and finds the length is 7 inches, the width is 14 inches, and the height is 15 inches. what is the volume of the box? [type your answer as a number.]

Ineed if you could explain and give me the answer you! this needs done

The square root of 9x plus 7 plus the square rot of 2x equall to 7