Question

1/1x2 + 1/2x3 + 1/3x4 + ...+1/999x1000

tính tổng giúp mình nhé

Answer 1

\(\frac{1}{1x2}+\frac{1}{1x3}+...+\frac{1}{999x1000}\)

\(=1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+...+\frac{1}{999}-\frac{1}{1000}\)

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

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

Answer 2

1/1x2+1/2x3+1/3x4+...+1/999x1000

=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

999 / 1000

Answer 4

kêt quả đúng là 1999/1000 cơ