[EPQ Vol 1A] Question 15

A rectangle field has width of \(\left( 5x-y \right)\) m. It is given that the length is twice of its width.

The owner of the field intends to install fence around the field. The cost of installing the fence on the sides of the width is \(\$55\) per metre and on the sides of the length is \(\$42\) per metre.

Find and simplify, in terms of \(x\) and \(y\), an expression for

1. the perimeter of the rectangle,
2. the total cost of installing the fences.