Can someonesolve this? i need it in less than an hour it’s urgent, you

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

Given f(x)= 9x+1 and g(x)=x^3, choose the expression (f*g)(x)

Which describes the difference between the graph of f(x)=x^2 and g(x)=-(x^2-2)