Select all the expressions below which represent a 20% discount off the price of an item that originally costs d dollars.
a. 0.8d
b. d-0.2
c. d-0.2d
d. 1-0.2d

Apulley with a mechanical advantage of 5 will require you to pull times the amount of rope. a. 1/5 b. 5 c. 10 d. 15

How many atoms of nitrogen are in the chemical formula ni(w on

Select all the correct answers. which changes will increase the rate of reaction during combustion? decreasing the area of contact between the reactants adding more oxygen to the reaction removing heat from the reaction changing the reactants from solid form to powdered form lowering the exposure of the reactants to air