Shaylynn has a square poster of a puppy on her bedroom wall. The width is one-third the length of the picture. If the width is 21 inches, write and solve an equation to determine the length. 3L = 21; L = 7 inches 3 + L = 21; L = 18 inches L − 3 = 21; L = 24 inches L over 3 equals 21; L = 63 inches

pls help im ina rush lol