Question

Problem: The length of a rectangle is 3cm more than twice its width. If the perimeter is

60cm, find its length.

Answer 1

16.5cm

Explanation:

`perimeter = 2(l + w)\\l = 3 + w\\perimeter = 60\\2(l + w) = 60\\sub (l = 3 + w) for - l\\2((3+w) + w) = 60\\2(3 + w + w) = 60\\2(3 + 2w) = 60\\6 + 4w = 60\\4w = 60 - 6\\4w = 54\\w = (54)/(4)\\w = 13.5\\\\substitute- w= 13- into 2(l = 3 + w)\\l = 13.5 + 3\\l = 16.5`