Remainder in 804 divided by 7

Determine whether the set of whole numbers is closed under addition. explain why the set is or is not closed. give an example.

Use the quadratic formula to solve the equation. if necessary, round to the nearest hundredth. x^2 - 20 = x a. 5, 4 b. -5, -4 c. -5, 4 d. 5, -4

Runner ran 1 4/5 miles on monday and 6 3/10 on tuesday. how many times her monday’s distance was her tuesdays distance