Question

Tính nhanh 2/3 + 2/6 + 2/12 + 2/24 + 2/48 + 2/96 + 2/192 .Đây là bài nâng cao mọi người làm giúp mình nhé

 

Answer 1

\(\dfrac{2}{3}+\dfrac{2}{6}+\dfrac{2}{12}+\dfrac{2}{24}+\dfrac{2}{48}+\dfrac{2}{96}+\dfrac{2}{192}\)

\(=2\times\left(\dfrac{1}{3}+\dfrac{1}{6}+\dfrac{1}{12}+\dfrac{1}{24}+\dfrac{1}{48}+\dfrac{1}{96}+\dfrac{1}{192}\right)\)

\(=2\times\left(\dfrac{64+32+16+8+4+2+1}{192}\right)\)

\(=\dfrac{127}{96}\)

Answer 2

=2/3+1/3+1/6+1/12+1/24+1/48+1/96

=\(\dfrac{127}{96}\)