Необходима помощь

1. вычислите:〖16〗^ (1/4) - (〖1/9) 〗^ (-1/2) + 〖27〗^ (1/3)

2. найти значение выражения cosπ/8*cos3π/8+sin5π/8*sin3π/8

3. найти корень уравнения: √ (-24-5 х) = 4

1) = 2^4·1/4 - 1/3 + 3^3·1/3 = 2 - 1/3 + 3 = 5 - 1/3 = 4 2/3

2) = Cos π/8 Sin 5π/8 + Sin 5π/8 Sin 3π/8 = Sin 5π/8 (Cos π/8 + Sin 3π/8) =

=Sinπ/8 (Cos π/8 - Cos 5π/8) = Sin π/8·2Sin 3π/4·Sin π/2 = 2 Sinπ/8 ·√2/2·1 = √2Sin π/8 = √2·√ (1 - √2/2) / 2) = √2/2·√ (2 - √2)

3) √ (-24 - 5 х) = 4 |²

-24 - 5x = 16

-5x = 40

x = - 8