3. Calculate the unknown value

Determine the value of \(x\) if the interior angle of the pentagon are \(∠P = (x-5)°\), \(∠Q = (x+15)°\), \(∠R = (x+5)°\), \(∠S = x°\) and \(∠T = (x-15)°\).

 

 

The value of \(x\) is$i\mathrm{°}$.