\(\frac{1}{1.5}+\frac{1}{5.9}+\frac{1}{9.13}+...+\frac{1}{97.101}\)
\(=\frac{1}{4}\left(1-\frac{1}{5}+\frac{1}{5}-\frac{1}{9}+\frac{1}{9}-\frac{1}{13}+...+\frac{1}{97}-\frac{1}{101}\right)\)
\(=\frac{1}{4}.\left(1-\frac{1}{101}\right)\)
\(=\frac{1}{4}.\frac{100}{101}\)
\(=\frac{25}{101}\)
Giải giúp mik bài toán
1/1.5+1/5.9+1/9.13+..+1/97.101
Cảm ơn nhiều^^
1/1.5 + 1/5.9 + 1/9.13 + 1/13.17 + .....+ 1/41.45
cb kb với mk nha
8/1.5+8/5.9+8/9.15+...+8/97.101
1/5.9+1/9.13+1/13.17+1/17.21+1/21.25
Tinh
A= 4/5.9 + 4/9.13 + 4/13.17 + ....+ 4/41.45
B= ( 1 - 1/2 ) . ( 1 - 1/3 ) . ( 1 - 1/4 ) ...... ( 1 - 1/100 )
Tính nhanh : ( Lưu ý : dấu ( . ) là dấu nhân )
\(A=\frac{1}{5.9}+\frac{1}{9.13}+\frac{1}{13.7}+...............+\frac{1}{100.104}\)
Tính nhanh:
H=2.2/1.5+2.2/5.9+2.2/9.13+......................+2.2/45.49
LƯU Ý: DẤU CHẤM LÀ NHÂN
B=1/1.5+1/5.9+1/9..13+1/13.17+1/17.21+1/21.25+1/25.29
D=1/1.5+1/5.9+...+1/41.45 Mn lm nhanh giúp mik vs ạ
