Plz help I'm on a quiz!

Solve each quadratic equation by factoring and using the zero product property. x^2 + 18x = 9x

Desmond wants to sell his car that he paid $8,000 for 2 years ago. the car depreciated, or decreased in value, at a constant rate each month over a 2-year period. if x represents the monthly depreciation amount, which expression shows how much desmond can sell his car for today? \ 8,000 + 24x 8,000 - 24x 8,000 + 2x 8,000 - 2x

Cd is the perpendicular bisector of both xy and st, and cy=20. find xy.