Question

a=1/1.2+1/2.3+...+1/99.100

Answer 1

a=1-1/2+1/2-1/3+ ....+1/99-1/100=1-1/100=99/100

Answer 2

A=1-1/2+1/2-1/3+.....+1/99-1/100

  = 1-1/100

  = 99/100

Answer 3

\(A=1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+...+\frac{1}{99}-\frac{1}{100}\)

\(=1-\frac{1}{100}\)

\(=\frac{99}{100}\)
 

Answer 4

=1/1-1/2+1/2-1/3+...+1/99-1/100

=1-1/100

=99/100