Question

\(\dfrac{1}{3.4}+\dfrac{1}{4.5}+\dfrac{1}{5.6}+...+\dfrac{1}{200.201}\)

Answer 1

\(\dfrac{1}{3.4}+\dfrac{1}{4.5}+\dfrac{1}{5.6}+...+\dfrac{1}{200.201}\)

=\(\dfrac{1}{3}-\dfrac{1}{4}+\dfrac{1}{4}-\dfrac{1}{5}+\dfrac{1}{5}-\dfrac{1}{6}+...+\dfrac{1}{200}-\dfrac{1}{201}\)

=\(\dfrac{1}{3}-\dfrac{1}{201}\)

=\(\dfrac{67}{201}-\dfrac{1}{201}\)

=\(\dfrac{66}{201}\)

                         ---Học Tốt Nha---

Answer 2

Giải:

1/3.4+1/4.5+1/5.6+...+1/200.201

=1/3-1/4+1/4-1/5+1/5-1/6+...+1/200-1/201

=1/3-1/201

=22/67

Chúc bạn học tốt!