4. The width of a rectangular sports pitch is \(x\) metres, \(x > 0\). The length of the pitch is 20 m more than its width. Given that the perimeter of the pitch must be less than 300 m ,
- form a linear inequality in \(x\).
Given that the area of the pitch must be greater than \(4800 \mathrm {~m} ^ { 2 }\),
- form a quadratic inequality in \(x\).
- by solving your inequalities, find the set of possible values of \(x\).