Which of the following is a function
please help!!

Idont understand math at all! : o( use this scenario to answer the remaining questions: brenton purchased a new bedroom set for $4,500.00. he lives in arizona and pays a 8.75% sales tax. if he made a 50% down payment and financed the rest, what amount did he finance? what is the total sales tax brenton will pay? enter your answer in currency format, round to the nearest cent. what was brenton's total amount financed? enter your answer in currency format, round to the nearest cent.

In which direction does the left side of the graph of this function point? f(x) = 3x3 - x2 + 4x - 2

What is the t intercept of the line given by the equation below y= -10x + 14