Medical researchers have determined that for exercise to be beneficial, a person’s desirable heart rate, r, in beats per minute, can be approximated by the formulas where a represents the person’s age. if the desirable heart rate for a man is 135 beats per minute, how old is he?

Maryann’s friends loved her bulletin board, and 4 of them asked her to make one for their homes. she offered to make each of her friends a replica of her bulletin board that measures 2 meters by 3 meters. how many kilograms of burlap should maryann collect to complete the bulletin boards for her friends? maryann should collect kg of burlap.