Question

the length of a rectangle is 5 cm less than 3 time its width. if the perimeter of the rectangle is 54 cm, find the length and width

Answer 1

$length = 3x - 5 \\ width \: = x \\ p = 2l + 2w \\ 54 = 2(3x - 5) + 2x \\ 54 = 6x - 10 + 2x \\ 54 = 8x - 10 \\ 64 = 8x \\ x = 8 = width \\ 3(8) - 5 = 24 - 5 = 19 \\ length = 19$