Does anyone know the answer to this?

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

Let f(x) = 5/x and g(x)=2x2+5x. what two numbers are not in the domain of f o g

Use pascal's triangle to find the missing values. x4 - 4xb + 6x2 - ax + 1