What is the domain of the function shown in the table

HELP

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

Which of the following graphs could represent a quartic function?

X^2/100+y^2/25=1 the length of the major axis is: a)5 b)10 c)20