Question

Tính giá trị biểu thức 

A= 2/7×7/15-2/3×5/27chia cho -4/9×7/15+4/9×5/27

 

Answer 1

A =\(\frac{2}{7}\times\frac{7}{15}-\frac{2}{3}\times\frac{5}{27}\) =\(\frac{14}{105}-\frac{10}{81}\)=\(\frac{2}{15}-\frac{10}{81}\)=\(\frac{162}{1215}-\frac{150}{1215}\)=\(\frac{12}{1215}\)

\(\frac{-4}{9}\times\frac{7}{15}+\frac{4}{9}\times\frac{5}{27}\)=\(\frac{-28}{135}+\frac{20}{243}\)=\(\frac{-6804}{32805}+\frac{2700}{32805}\)=\(\frac{-4104}{32805}\)=\(\frac{-152}{1215}\)

A=\(\frac{2}{7}\times\frac{7}{15}-\frac{2}{3}\times\frac{5}{27}\)chia cho\(\frac{-4}{9}\times\frac{7}{15}+\frac{4}{9}\times\frac{5}{27}\)

  = \(\frac{12}{1215}:\frac{-152}{1215}\)

  =\(\frac{12}{1215}\times\frac{1215}{-152}\)

  =\(\frac{14580}{-184680}\)

Answer 2

\(\frac{14580}{-184680}\)rút gọn bằng\(\frac{-3}{38}\)