Question

Equação exponencial $2^{x+1}+2^{2-x}=9$

Answer 1

Ola Andre

2^(x + 1) + 2^(2 - x) = 9

2*2^x + 4/2^x = 9

2*(2^x)^2 - 9*2^x + 4 = 0

y = 2^x

2y^2 - 9y + 4 = 0

delta
d^2 = 81 - 32 = 49
d = 7

y1 = (9 + 7)/4 = 16/4 = 4
y2 = (9 - 7)/4 = 2/4 = 1/2

y = 2^x

4 = 2^x --> x = 2
1/2 = 2^x --> x = -1

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