HELP ME PLEASE DID I DO THIS RIGHT

The larger of two number is 4 less than twice the smaller number. the sum is 41. find the numbers

Apinhole camera is made out of a light-tight box with a piece of film attached to one side and pinhole on the opposite side. the optimum diameter d(in millimeters) of the pinhole can be modeled by d=1.9[ (5.5 x 10^-4) l) ] ^1/2, where l is the length of the camera box (in millimeters). what is the optimum diameter for a pinhole camera if the camera box has a length of 10 centimeters

Three people are traveling and need to exchange the currency of their native country for the currency of the country they are visiting. drag each exchange to the category that shows the ratio of currencies in that exchange.