Question

[Khánh Vinh]

Thực hiện phép tính

a) \(\frac{5}{16}:0,125-\left(2\frac{1}{4}-0,6\right).\frac{10}{11}\)

b) \(\frac{3}{5.8}+\frac{3}{8.11}+.....+\frac{3}{2012.2015}\)

Answer 1

[Bellion]

              Bài làm :

\(\text{a)}=2,5-1,65.\frac{10}{11}=2,5-1.5=1\)

\(b\text{)}=\frac{8-5}{5.8}+\frac{11-8}{8.11}+...+\frac{2015-2012}{2012.2015}\)

\(=\frac{1}{5}-\frac{1}{8}+\frac{1}{8}-\frac{1}{11}+\frac{1}{11}-...+\frac{1}{2012}-\frac{1}{2015}\)

\(=\frac{1}{5}-\frac{1}{2015}\)

\(=\frac{402}{2015}\)

Answer 2

[Nguyễn Hà Chi]

\(a,\frac{5}{16}:0,125-\left(2\frac{1}{4}-0,6\right).\frac{10}{11}\)

\(=\frac{5}{16}:\frac{1}{8}-\left(\frac{9}{4}-\frac{3}{5}\right).\frac{10}{11}\)

 \(=\frac{5}{2}-\frac{33}{20}.\frac{10}{11}\)

\(=\frac{5}{2}-\frac{3}{2}=\frac{2}{2}=1\)