FREE POINTS because i passed my midterms

The area of a rectangle is 15+5y square feet. which of the following expressions could be the length of the sides of the rectangle, in feet a. 5 and 3y b. 5 and 3+y c. 5 and 5+y d. 3 and 5+3y

Evaluate the function , when d = {9, 15, 30}. r = {5, 7, 12} r = {6, 10, 15} r = {6, 10, 20} r = {5, 12, 20}

Using only the digits 5, 6, 7, 8, how many different three digit numbers can be formed if no digit is repeated in a number?