Question
Solve$ : 3(2^x+ 1) - 2^{x+2}+ 5 = 0.$
✓
Answer
$3(2^x+ 1) - 2^{x+2}+ 5 = 0.$
$\Rightarrow 3 \times 2^x + 3 - 2^x \times 2^2 + 5 = 0$
$\Rightarrow 2^x( 3 - 2^2 ) + 8 = 0$
$\Rightarrow 2^x( 3 - 4 ) = - 8$
$\Rightarrow 2^x x ( - 1 ) = - 8$
$\Rightarrow 2^x = 8$
$\Rightarrow 2^x = 2^3$
$\Rightarrow x = 3$
$\Rightarrow 3 \times 2^x + 3 - 2^x \times 2^2 + 5 = 0$
$\Rightarrow 2^x( 3 - 2^2 ) + 8 = 0$
$\Rightarrow 2^x( 3 - 4 ) = - 8$
$\Rightarrow 2^x x ( - 1 ) = - 8$
$\Rightarrow 2^x = 8$
$\Rightarrow 2^x = 2^3$
$\Rightarrow x = 3$
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