There's a sale of 25% off of a $45 pair of sunglasses how much is the discount ? What is the sale price ?

The pressure exerted on the walls of a container by a gas enclosed within it is directly proportional to the temperature of the gas. if the pressure is 6 pounds per square inch when the temperature is find the pressure exerted when the temperature of the gas is 380 degrees f show work for the

If cos(2x) = tan^2(y), show that cos(2y) = tan^2(x).

If 30 lb of rice and 30 lb of potatoes cost ? $27.60? , and 20 lb of rice and 12 lb of potatoes cost ? $15.04? , how much will 10 lb of rice and 50 lb of potatoes? cost?