Question

4•2^x + 2^x-1 = 72

Ajuda ae pessoal

Answer 1

vamos lá

$4.2^x+2^{x-1}=72 \\ \\ 4.2^x+2^x.2^{-1}=72 \\ \\ 2^x(4+2^{-1})=72 \\ \\ 2^x(4+ \frac{1}{2} )=72 \\ \\ 2^x( \frac{8+1}{2} )=72 \\ \\ 2^x( \frac{9}{2} )=72 \\ \\ 2^x=72\div \frac{9}{2} \\ \\ 2^x=\not72^8\times \frac{2}{\not9} \\ \\ 2^x=8\times2 \\ \\ 2^x=16 \\ \\\not 2^x=\not 2^4 \\ \\ x=4$

Answer 2

$4.2^{x}+2^{x-1}=72 \\ \\ 4.2^{x}+ \frac{2^{x}}{2} = 72 \\ \\ y = 2^{x} \\ \\ 4.y+ \frac{y}{2} = 72 \\ \\ 8.y + y = 144 \\ \\ 9y = 144 \\ \\ y = \frac{144}{9} \\ \\ y = 16 \\ \\ y = 2^{x} \\ \\ 16 = 2^{x} \\ \\ 2^{4}= 2^{x} \\ \\ x = 4$

Espero ter ajudado.