Question

tinh

1/1.3+1/2.3+1/3.4+...+1/99.100

 

Answer 1

=1-1/3+1/2-1/3+1/3-1/4+....+1/99-1/100

=1-1/100

=99/100

ai kick mkmk kich lai 5 h

Answer 2

= 1 - 1/2 + 1/2 - 1/3 + 1/3 - 1/4 + ... + 1/999 - 1/1000

= 1 - 1/1000

= 1000/1000 - 1 /1000

= 999/1000

Answer 3

rối rắm lắm 

mà cho mình đi mình lại

Answer 4

\(\frac{1}{1.3}+\frac{1}{2.3}+\frac{1}{3.4}+.........+\frac{1}{99.100}\)

\(=1-\frac{1}{1000}\)

\(=\frac{1000}{1000}-\frac{1}{1000}\)

\(=\frac{999}{1000}\)

Answer 5

1/1.3+1/2,3+1/3,4+...+1/99.100

=1-1/100

=999/100

Answer 6

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

=1/100-1

=99/100