Ответ:\(8x + 7x = 1515\)\(15x = 1515\)\(x = 101\).\(8 \cdot (2x - 6) = 128\)\(2x - 6 = 128 : 8 = 16\)\(2x = 22\)\(x = 11\).Ответ: а) \(x = 101\); б) \(x = 11\).