Решите уравнения: 1)6у4-5у2-6 = 0
2)4.5m4-9m2+4 = 0
3)(t2+8t)2+19 (t2+8t)+84 = 0
4)(2z2+11z)2-23 (2z2+11z)+126 = 0
5)(x2+3x+1)(x2+3x+3) = -1