Gọi A=1/1x6+1/6x11+1/11x16+...+1/96x101
A=1/1x6+1/6x11+1/11x16+...+1/96x101
5A=5/1x6+5/6x11+5/11x16+...+5/96x101
5A=1-1/6+1/6-1/11+1/11-1/16+...+1/96-1/101
5A=1-1/101
5A=100/101
A=100/101:5
A=20/101.
Nếu đúng thì kết bạn với mình nhé.Mình học lớp 6C của trường THCS An Khê.Tên Đỗ Đường Hùng.
= 1/5 . (5/1.6 + 5/6.11 + ...... + 5/96.101)
= 1/5 . (1-1/6+1/6-1/11+.....+1/96-1/101)
= 1/5.(1-1/101)
= 1/5 . 100/101
= 20/101
Tk mk nha
=1/1-1/6+1/6-1/11+1/11-1/16+...+1/96-1/101 =1-1/101=100/101
\(\Rightarrow5A=\frac{5}{1.6}+\frac{5}{6.11}+...+\frac{5}{96.101}.\)
\(\Leftrightarrow5A=1-\frac{1}{6}+\frac{1}{6}-\frac{1}{11}+\frac{1}{11}-...-\frac{1}{96}+\frac{1}{96}-\frac{1}{101}\)
\(\Leftrightarrow5A=1-\frac{1}{101}=\frac{100}{101}\)
\(\Rightarrow A=\frac{100}{101}:5=\frac{100}{101}.\frac{1}{5}=\frac{20}{101}\)
VẬY \(A=\frac{20}{101}\)
A=1/1x6+1/6x11+1/11x16+...+1/96x101
5A=5/1x6+5/6x11+5/11x16+...+5/96x101
5A=1-1/6+1/6-1/11+1/11-1/16+...+1/96-1/101
5A=1-1/101
5A=100/101
A=100/101:5
A=20/101.
