Помогите!!! решить неравенства

Question

Помогите!!! решить неравенства

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Answer 1

4^x - 2^(x + 1) - 8 < 0
4^x - 2^x*2 - 8 < 0

2^x = t
t^2 - 2t - 8 < 0
t^2 - 2t - 8 = 0 
D = 4 + 32 = 36 
t1 = (2 + 6)/2 = 8/2 = 4
t2 = (2 - 6)/2 = - 4/2 = - 2 

2^x = 4
x = 2

x - 2 < 0
x < 2

x ∈ ( - ∞; 2)