2/3+2/15+2/35+...+2/n x (n+2) = 322/323
2/1x3+2/3x5+2/5x7 +...+ 2/nx(n+2) = 322/323
1-1/3+1/3-1/5+1/5-1/7+...+1/n-1/(n+2) = 322/323
1-1/n+2 = 322/323
1/n+2 = 1-322/323
1/n+2 = 1/323
=> n+2 = 323
n = 323 - 2 = 321
2/3+2/15+2/35+...+2/n x (n+2) = 322/323
2/1x3+2/3x5+2/5x7 +...+ 2/nx(n+2) = 322/323
1-1/3+1/3-1/5+1/5-1/7+...+1/n-1/(n+2) = 322/323
1-1/n+2 = 322/323
1/n+2 = 1-322/323
1/n+2 = 1/323
=> n+2 = 323
n = 323 - 2 = 321
Find n such that: 2/3 + 2/15 + 2/35 + ...... + 2/n = 322/323
Find n such that: 2/3+2/15+2/35+...+ 2/ nx(n+2)=322/323
tìm n biết
2/3+2/15+2/35+..........+2/n=322/323
Dấu / là gạch phân số.
Tìm N biết
\(\frac{2}{3}+\frac{2}{15}+\frac{2}{35}+...+\frac{2}{N}=\frac{332}{323}\)
2/3 + 2/15 + 2/ 35+...+ 2/n=60/61 . Vay n=...
tìm số tự nhiên n biết : 2/3+2/15+2/35+2/63+...+2/n = 100/101
2/3+2/15+2/35+...+2/n=60/61(hướng dẫn cách giải), Tìm n
\(\frac{2}{3}+\frac{2}{15}+\frac{2}{35}+.....+\frac{2}{n}=\frac{60}{61}\).Tìm giá trị của n.
3/5+3/15+3/35+3/63+............+3/nx(n+2)=3015/2011