1,
x10 = x
=> x10 - x = 0
=> x(x9 - 1) = 0
=> \(\orbr{\begin{cases}x=0\\x^9-1=0\end{cases}}\)
=> \(\orbr{\begin{cases}x=0\\x^9=1\end{cases}}\)
=> \(\orbr{\begin{cases}x=0\\x=1\end{cases}}\)
KL: x thuộc {1; 0}
2,
\(S=2+2^2+2^3+...+2^{2016}\)
=> \(2S=2^2+2^3+2^4+...+2^{2017}\)
=> \(2S-S=\left(2^2+2^3+2^4+...+2^{2017}\right)-\left(2+2^2+2^3+...+2^{2016}\right)\)
=> \(S=2^{2017}-2\)
Bài 1:
x10 = x => x= { -1;1}
Bài 2:
\(S=2+2^2+2^3+...+2^{2016}\)
\(2S=2^2+2^3+2^4+2^{2017}\)
\(2S-S=2^{2017}-2\)
Vậy \(S=2^{2017}-2\)
2.Tính: S= 2 + 22 + 23 + ....... + 22016
=> 2S = 22 + 23 + ....... + 22016
=> 2S - S = 22016 - 2
=> S = 22016 - 2
S = 2 + 22 + 23 + .... +22016
=> 2S = 22 + 23 + .... +22017
=> 2S -S = 22017 - 1
=> S =22017 - 1