Three more than eight times a number is equal to 19

Aquadratic equation in standard from is written ax^2= bx+c, where a, b and c are real numbers and a is not zero?

Linda loans her friend $250 with a 5% monthly intrest rate. how much was the whole loan?

Melanie is buying a bathing suit that costs 39.99. she is given a discount at the cash register of $6.00 when she scratched 15% off on a game piece for a store promotion. what will the sale price of melanie’s bathing suit be?