What is 42 1/2 ×28 and then divided by 2

What is the name used to describe a graph where for some value of x, there exists 2 or more different values of y?

Ifurniture stores having a weekend sale and is offering 20% discount on patio chairs and table the sales tax on furniture is 6.25 using function composition how can you represent the total amount a that you would need to pay for this furniture that cost x dollars

What is the total surface area of this square pyramid?