Помогите решить логорифмы

Это слово пишется через а: логарифм.

1. А) (1/4)^(-log2(5)) = (2^(-2))^(-log2(5)) = 2^(2*log2(5)) = 2^(log2(5^2)) = 5^2 = 25

Б) 81^(log9(2)) = (9^2)^(log9(2)) = 9^(log9(2^2)) = 2^2 = 4

В) log2(5) - log2(35) + log2(56) = log2(5/35*56) = log2(1/7*7*8) = log2(8) = 3

Г) log12(3) + log12(4) = log12(3*4) = log12(12) = 1

2. A) log5(0,008/125) = log5(0,008) - log5(125) = log5(1/125) - 3 = - 3 - 3 = - 6

Б) log3 (log4 (4^(1/9))) = log3 (1/9) = - 2

В) log7(64) - log7(256) + log7(28) = log7(64/256*28) = log7(1/4*4*7) = log7(7) = 1

3. A) y = ln(x - 7)

x - 7 gt; 0

x (7; +oo)

Б) y = log2(3 - x^2)

3 - x^2 gt; 0

x^2 lt; 3

x (-3; 3)

В) y = ln (tg (x/2))

tg (x/2) gt; 0

x/2 (pi*k; pi/2+pi*k)

x (2pi*k; pi+2pi*k)

Г) y = 4x^2 + 7x + 3

x (-oo; +oo)