A swimming pool manufacturer installs rectangular pools whose length is twice the width, plus 5m. Find a simplified algebraic expression that describes the total length of coping needed. Include a labelled diagram in your solution for full marks.

Answer 1

L = (2 w+5)
perimeter =2 L + 2 w
= 2*(2w+5) + 2 w
= 4 w+ 10 + 2 w
= 6 w + 10