1-1/2+1/2-1/3+......+1/n - 1/(n+1) = 98/99
1-1/(n+1)=98/99
1/(n+1) = 1-98/99
1/(n+1) = 1/99
=> n+1 = 99
=> n=99 -1
=> n=98
1-1/2+1/2-1/3+......+1/n - 1/(n+1) = 98/99
1-1/(n+1)=98/99
1/(n+1) = 1-98/99
1/(n+1) = 1/99
=> n+1 = 99
=> n=99 -1
=> n=98
\(\Leftrightarrow1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+..............+\frac{1}{n}-\frac{1}{n+1}=\frac{98}{99}\)
\(\Rightarrow1-\frac{1}{n+1}=\frac{98}{99}\)
\(\Rightarrow\frac{1}{n+1}=1-\frac{98}{99}\)
\(\Rightarrow\frac{1}{n+1}=\frac{1}{99}\)
\(\Rightarrow n+1=99\)
\(\Rightarrow n=98\)
