Given an isosceles triangle \(\Delta PQR\), \(PQ = PR\). The measures of \(\angle P\) and \(\angle Q\) are \((2x + 30)^\circ\) and \((3x - 15)^\circ\), respectively.
(a) The value of \(x\) is
(b) The measure of \(\angle P\) is
(c) The measure of \(\angle Q\) is
(d) The measure of \(\angle R\) is
Answer variants:
\(75^\circ\)
\(22.5^\circ\)
\(52.5^\circ\)
\(85^\circ\)
\(30^\circ\)
\(20^\circ\)
\(50^\circ\)
\(25^\circ\)