Help me plz I need and answer ASAP!

Are carpet coast $15 per square metre. the total delivery charge is $21 peter buys n squared metres of carpet what is the expression which represents the total cost in $

What is the standard form of -5x^2+2x^4-11+x^3+3x

Omar is going on a road trip! the car rental company offers him two types of cars. each car has a fixed price, but he also needs to consider the cost of fuel. the first car costs $90 to rent, and because of its fuel consumption rate, there's an additional cost of s0.50 per kilometer driven.