Zack paid for a DVD with a $20 bill. The price of the DVD was $19.50. How many combinations of nickels, dimes, and quarters are possible as change for $0.50?

Type the correct answer in the box. consider the system of linear equations below. rewrite one of the two equations above in the form ax + by = c, where a, b, and c are constants, so that the sum of the new equation and the unchanged equation from the original system results in an equation in one variable.