What is the missing length

If you want to place an 8 ½ inch towel bar in the center of a door that is 25 ½ wide, how much space will be on each side of the towel bar?

Asystem of equations has 1 solution.if 4x-y=5 is one of the equations , which could be the other equation ?

An investment decreases in value by 30% in the first year and decreases by 40% in the second year. what is the percent decrease in percentage in the investment after two years