Can someone walk me through this?

Mustafa contributes 11% of his $67,200 annual salary to his 401k plan. what is his pretax income

Factor this polynomial completely x^2-64

The perimeter of a rectangular lot of land is 436 ft. this includes an easement of x feet of uniform width inside the lot on which no building can be done. if the buildable area is 122 ft by 60 ft, determine the width of the easement. select one: a. 9 feet b. 18 feet c. 4.5 feet d. 7 feet