What is the simplified form of x to the fourth power -81 over x+3? does anyone know the rest of the answers for the quick check?

Carl wants to buy a television that cost $500 including taxes. to pay for television he will use a payment plan that requires him to make a down payment of $125 and then pay $70.50 each month for six months what is the percent increase from the original cast of the television to the cost of the television using a payment plan.

The product of two negative rational numbers is always zero sometimes zero never zero

What is the result of adding the system of equations? 2x+y=4 3x-y=6