How many liters of pure water should be mixed with a 16-L solution of 80% acid to produce a mixture that is 80% water

Evaluate the discriminant of each equation. tell how many solutions each equation has and whether the solutions are real or imaginary. x^2 - 4x - 5 = 0

Varies inversely with x. if y=8.5 when x=-1 find x when y=-1

Atotal of 766 tickets were sold for the school play. they were either adult tickets or student tickets. there were 66 more student tickets sold than adult tickets. how many adult tickets were sold?