Question

Задание по алгебре 8 класс

Answer 1

$2^{3-k}+2^{1-k}+5\cdot 2^{-k}=40\\\\2^3\cdot 2^{-k}+2\cdot 2^{-k}+5\cdot 2^{-k}=40\\\\2^{-k}\cdot (2^3+2+5)=40\\\\2^{-k}\cdot 15=40\\\\2^{-k}= \frac{40}{15}\\\\2^{-k}=2 \frac{2}{3}$

Answer 2

$2^{3-k}+ 2^{1-k}+5* 2^{-k}=40\\\\ 2^{3}* 2^{-k} + 2^{1}* 2^{-k} +5* 2^{-k}=40\\\\8* 2^{-k}+2* 2^{-k} +5* 2^{-k}=40\\\\15* 2^{-k}=40\\\\ 2^{-k} =2 \frac{2}{3}$