The length of a rectangle is 4 more than 3 times the width. If the perimeter of the rectangle is 56, what is the length of the rectangle

The relation between the width and the length is : l = 3w + 4 - - eqn (1) Perimeter = 56 " 2w + 2l = 56 Dividing through by 2 gives; w + l = 28 w = 28 - l - - eqn (2) Substitute eqn (2) in eqn (1) " l = 3 (28-l) + 4 Expanding bracket gives; l = 84 - 3l + 4 Grouping like terms, we have; l + 3l = 84+4 4l = 88 l = 88/4 l = 22 The length of the rectangle is 22 units.