(х²-5х)²-4(х²-5х)=12
обозначим х²-5х=у
у²-4у-12=0
у₁=4+√(16+48) = 4+8 = 6
2 2
у₂=4-√(16+48) = 4-8 = -2
2 2
х²-5х=6
х²-5х-6=0
х₁=5+√(25+24) = 5+7 = 6
2 2
х₂=5-√(25+24) = 5-7 = -1
2 2
х²-5х=-2
х²-5х+2=0
х₃=5+√(25-8) = 5+√17
2 2
х₄=5-√(25-8) = 5-√17
2 2