Question

5/6 + 5/12+ 5/20+.........5/132    mình đang cần gấp 

 

Answer 1

Đặt \(A=\frac{5}{6}+\frac{5}{12}+\frac{5}{20}+...+\frac{5}{132}\)

\(A=\frac{5}{2.3}+\frac{5}{3.4}+\frac{5}{4.5}+...+\frac{5}{11.12}\)

\(A=5\left(\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+...+\frac{1}{11}-\frac{1}{12}\right)\)

\(A=5\left(\frac{1}{2}-\frac{1}{12}\right)\)

\(A=5\times\frac{5}{12}\)

\(A=\frac{25}{12}\)

Answer 2

ai làm nhanh mình k gấp đôi ha

Answer 3

=\(\frac{5}{6}\)+ \(\frac{5}{12}\)+ ...+ \(\frac{5}{132}\)

= \(\frac{5}{2.3}\)+ \(\frac{5}{3.4}\)+ ...+ \(\frac{5}{11.12}\)

= \(\frac{5}{2}\)- \(\frac{5}{3}\)+ \(\frac{5}{3}\)- \(\frac{5}{4}\)+ ...+ \(\frac{5}{11}\)- \(\frac{5}{12}\)

= \(\frac{5}{2}\)- \(\frac{5}{12}\)

= \(\frac{25}{12}\)

Answer 4

cam on ban nha'

Answer 5

\(\frac{5}{6}+\frac{5}{12}+\frac{5}{20}+...+\frac{5}{132}\)

\(=\frac{5}{2.3}+\frac{5}{3.4}+\frac{5}{4.5}+...+\frac{5}{11.12}\)

\(=5\left(\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+\frac{1}{4}-\frac{1}{5}+...+\frac{1}{11}-\frac{1}{12}\right)\)

\(=5\left(\frac{1}{2}-\frac{1}{12}\right)\)

\(=5\cdot\frac{5}{12}=\frac{25}{12}\)