Question

1/3*4+1/4*5+1/5*6+...+1/11*12=?

Answer 1

1/3*4+1/4*5+1/5*6+...+1/11*12

=1/3-1/4+1/4-1/5+1/5-1/6+...+1/11-1/12

=1/3-1/12

=/4

nhé

Answer 2

\(=\frac{1}{3}-\frac{1}{4}+\frac{1}{4}-\frac{1}{5}+\frac{1}{5}-\frac{1}{6}+\frac{1}{6}-\frac{1}{7}+\frac{1}{7}-\frac{1}{8}+\frac{1}{8}-\frac{1}{9}+\frac{1}{9}-\frac{1}{10}+\frac{1}{10}-\frac{1}{11}+\frac{1}{11}-\frac{1}{12}\)

\(=\frac{1}{3}-\frac{1}{12}=\frac{1}{4}\)