б) log$$\frac{1}{4}$$(x2 + 6x) = -2
x2 + 6x = ($$\frac{1}{4}$$)-2
x2 + 6x = 42
x2 + 6x = 16
x2 + 6x - 16 = 0
D = 36 + 64 = 100
x1 = $$\frac{-6 + 10}{2}$$ = 2
x2 = $$\frac{-6 - 10}{2}$$ = -8
Проверка:
x = 2: log$$\frac{1}{4}$$(4 + 12) = log$$\frac{1}{4}$$16 = -2
x = -8: log$$\frac{1}{4}$$(64 - 48) = log$$\frac{1}{4}$$16 = -2
Ответ: -8; 2