Tuyển Cộng tác viên Hoc24 nhiệm kì 26 tại đây: https://forms.gle/dK3zGK3LHFrgvTkJ6
\(\frac{1}{1.2}+\frac{1}{2.3}+\frac{1}{3.4}+...+\frac{1}{x.\left(x+1\right)}=201\)
\(1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+...+\frac{1}{x}-\frac{1}{x+1}=201\)
\(1-\frac{1}{x+1}=201\)
\(\frac{1}{x+1}=1-201\)
\(\frac{1}{x+1}=-200\)
\(\Rightarrow x+1=-\frac{1}{200}\)
\(x=-\frac{1}{200}-1\)
\(x=-\frac{201}{200}\)
Vậy \(x=-\frac{201}{200}\)
1/1.2+1/2.3+1/3.4+...+1/x(x+1)=2/3
1/1.2+1/2.3+1/3.4+...+1/x.(x+1)=2015/2016
1/1.2+1/2.3+1/3.4+...+1/x.(x+1)=19/20
(1/1.2 +1/2.3 1/3.4 + ....+1/8.9) x=23/45
(1/1.2 +1/2.3 1/3.4 + ....+1/8.9) x=23/45
Tìm x:
a) |x - 2/5| =2,1
b)1/1.2+1/2.3+1/3.4+.......+1/x(x+1)=889/890
Tìm x, biết
1/1.2+1/2.3+1/3.4+...........+1/x.(x+1)= 2017/2018
giúp mìn với 1/1.2 +1/2.3+1/3.4+1/4.5+....+1/[x-1].x+1/x.[x+1]
(1/1.2+1/2.3+1/3.4+…+1/49.50)x=49/50
