Question

A=1/2.5+1/5.8+1/8.11+....+1/92/95+1/95/98

Answer 1

Tham khảo tại link này nhé : https://olm.vn/hoi-dap/detail/79256477545.html

hoặc vô câu hỏi tương tự cx có đó

Answer 2

\(A=\frac{1}{2.5}+\frac{1}{5.8}+...+\frac{1}{95.98.}\)

\(A=\frac{1}{3}.\left(\frac{3}{2.5}+\frac{3}{5.8}+...+\frac{3}{95.98}\right)\)

\(A=\frac{1}{3}.\left(\frac{1}{2}-\frac{1}{5}+\frac{1}{5}-\frac{1}{8}+...+\frac{1}{95}-\frac{1}{98}\right)\)

\(A=\frac{1}{3}.\left(\frac{1}{2}-\frac{1}{98}\right)\)

\(A=\frac{1}{3}.\frac{24}{49}\)

\(A=\frac{8}{49}\)

Answer 3

Trong câu hỏi tương tự có bạn ạ tham khảo nhé

~Hok tốt~

Answer 4

\(A=\frac{1}{2.5}+\frac{1}{5.8}+\frac{1}{8.11}+...+\frac{1}{92.95}+\frac{1}{95.98}\)

\(A=\frac{1}{3}.\left(\frac{1}{2}-\frac{1}{5}+\frac{1}{5}-\frac{1}{8}+\frac{1}{8}-\frac{1}{11}+...+\frac{1}{92}-\frac{1}{95}+\frac{1}{95}-\frac{1}{98}\right)\)

\(A=\frac{1}{3}.\left(\frac{1}{2}-\frac{1}{98}\right)\)

\(A=\frac{1}{3}.\frac{24}{49}\)

\(A=\frac{8}{49}\)

Answer 5

\(A=\frac{1}{2.5}+\frac{1}{5.8}+...+\frac{1}{92.95}+\frac{1}{95.98}\)

\(A=\frac{1}{3}.\left(\frac{1}{2}-\frac{1}{5}+\frac{1}{5}-\frac{1}{8}+...+\frac{1}{92}-\frac{1}{95}+\frac{1}{95}-\frac{1}{98}\right)\)

\(A=\frac{1}{3}.\left[\frac{1}{2}+\left(\frac{1}{5}-\frac{1}{5}\right)+\left(\frac{1}{8}-\frac{1}{8}\right)+...+\left(\frac{1}{95}-\frac{1}{95}\right)-\frac{1}{98}\right]\)

\(A=\frac{1}{3}.\left[\frac{1}{2}-\frac{1}{98}\right]\)

\(A=\frac{1}{3}.\frac{24}{49}=\frac{8}{49}\)

~ Hok tốt ~