PLEASE HELP ME!! please

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.

Chanelle deposits $7,500 into the bank. she does not withdraw or deposit money for 6 years. she earns 6% interest during that time. what will the balance be when she is finally able to withdraw her money?

The general form of the quetion of a circle is ax^2+by^2+cx+dy+e=0 where a=b=0 if the circle has a radius of three units and the center lies on the y axis which set of values of a, b, c, d, and e might correspond to the circle