Question

A=2¹⁰+1/2⁹+1 B=2¹²+1/2¹¹+1            so sánh giúp đi

              

Answer 1

Lời giải:

$A=\frac{2^{10}+2-1}{2^9+1}=\frac{2(2^9+1)-1}{2^9+1}=2-\frac{1}{2^9+1}$

$B=\frac{2^{12}+1}{2^{11}+1}=\frac{2(2^{11}+1)-1}{2^{11}+1}=2-\frac{1}{2^{11}+1}$

Vì $2^9+1< 2^{11}+1\Rightarrow \frac{1}{2^9+1}> \frac{1}{2^{11}+1}$

$\Rightarrow 2-\frac{1}{2^9+1}< 2-\frac{1}{2^{11}+1}$

$\Rightarrow A< B$