\(A=2^{17}-\left(1+2+2^2+...+2^{16}\right)\)

đặt \(1+2+2^2+...+2^{16}=B\Rightarrow A=2^{17}-B\)

\(B=1+2+2^2+...+2^{16}\)

\(2B=2+2^2+2^3+...+2^{17}\)

\(B=2B-B=\left(2+2^2+...+2^{17}\right)-\left(1+2+...+2^{16}\right)\)

\(B=2^{17}-1\)

\(A=2^{17}-B=2^{17}-\left(2^{17}-1\right)=2^{17}-2^{17}+1=1\)

Vậy A=1

3,75 . n + n . 4,92 = 867

=> n( 3,75 + 4,92 ) = 867

=> 8,67n = 867

           n = 867 : 8,67 

           n = 100