What is value a for 81xsquared -49

Asphere has a diameter of 10 in. what is the volume of the sphere?

Tom is the deli manager at a grocery store. he needs to schedule employee to staff the deli department for no more that 260 person-hours per week. tom has one part-time employee who works 20 person-hours per week. each full-time employee works 40 person-hours per week. write and inequality to determine n, the number of full-time employees tom may schedule, so that his employees work on more than 260 person-hours per week. graph the solution set to this inequality.

Write 5(6x+4)-2(5x-2) in the form a(bx+c) where a,b and c integers and a> 1