Question

Giải hộ minh với:

B=5/2.1+4/1.11+3/11.2+1/2.15+13/15.4

Answer 1

\(\frac{5}{2.1}+\frac{4}{1.11}+\frac{3}{11.12}+\frac{1}{2.15}+\frac{13}{15.4}\)

\(=\left(\frac{4}{1.11}+\frac{3}{11.12}\right)+\left(\frac{1}{2.15}+\frac{13}{15.4}\right)+\frac{5}{2.1}\)

\(=\frac{1}{11}\left(4+\frac{1}{4}\right)+\frac{1}{15}\left(\frac{1}{2}+\frac{13}{4}\right)+\frac{5}{2.1}\)

\(=\frac{1}{11}.\frac{17}{4}+\frac{1}{15}.\frac{17}{4}+\frac{5}{2}\)

\(=\frac{17}{4}\left(\frac{1}{11}+\frac{1}{15}\right)+\frac{5}{2}\)

\(=\frac{17}{4}.\frac{26}{165}+\frac{5}{2}\)

\(=\frac{442}{660}+\frac{5}{2}\)

\(=\frac{221}{330}+\frac{825}{330}\)

\(=\frac{1046}{330}\)

\(=\frac{523}{165}\)