Determine the value \(QR\) of the triangle \(PQR\) if \(QS =\) 39\(x +\) 8 \(feet\) and \(SR =\) 38\(x +\) 19 \(feet\) and \(S\) is the midpoint of \(QR\).
 
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Length of the \(QR\) is  \(feet\).