Question

2(2x+1)-9.2x+4=0

`2^2x + 1 - 9.2 ^x + 4 = 0`
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Answer 1

`\displaystyle\2^(2x+1)-9\cdot 2^x+4=0 \quad ; \qquad \boxed{ 2^x=t \; ; \; 2^(2x)=t^2} \\\\2t^2-9t+4=0 \\\\D=81-32 =49 \\\\ t_1=(9+7)/(4) =4 \\\\ t_2=(9-7)/(4) =(1)/(2) \\\\1) \ 2^x=4 \Longrightarrow x_1=2 \qquad 2) \ 2^x=2^(-1)\Longrightarrow x_2=-1 \\\\Answer: \boxed{x_1=2 \quad ; \quad x_2=-1}`