If someone purchases a car and pays $1,500 in sales tax and the ticket price of the car is $23,499, What is the percent sales tax in that state

Acollege is planning to construct a rectangular parking lot on land bordered on one side by a highway. the plan is to use 680 feet of fencing to fence off the other three sides. what dimensions should the lot have if the enclosed area is to be a maximum?

How do you answer this question? (step by step)

Which shows the correct substitution of the values a,b and c from the equation 1=-2x+3x^2+1