Question

[Võ Thị Huệ]

\(\frac{4}{2x4}+\frac{4}{4x6}+\frac{4}{4x8}+...+\frac{4}{16x18}\)

Ai trả lời đúng mik sẽ theo dõi

Answer 1

[Trần Thanh Phương]

\(\frac{4}{2\cdot4}+\frac{4}{4\cdot6}+...+\frac{4}{16\cdot18}\)

\(=2\cdot\left(\frac{2}{2\cdot4}+\frac{2}{4\cdot6}+...+\frac{2}{16\cdot18}\right)\)

\(=2\cdot\left(\frac{1}{2}-\frac{1}{4}+\frac{1}{4}-\frac{1}{6}+...+\frac{1}{16}-\frac{1}{18}\right)\)

\(=2\cdot\left(\frac{1}{2}-\frac{1}{18}\right)\)

\(=2\cdot\frac{4}{9}\)

\(=\frac{8}{9}\)

Answer 2

[Trần Thanh Phương]

HISINOMA KINIMADO sửa đâu ?