Question

Tính bằng cách hợp lí nhất : \(\frac{2}{7}\times5\frac{1}{4}-\frac{2}{7}\times3\frac{1}{4}\)

Answer 1

\(\frac{2}{7}.5\frac{1}{4}-\frac{2}{7}.3\frac{1}{4}\)

= \(\frac{2}{7}.\left(5\frac{1}{4}-3\frac{1}{4}\right)\)

= \(\frac{2}{7}.2\)

= \(\frac{4}{7}\)

Answer 2

\(=\frac{2}{7}\times\left(5\frac{1}{4}-3\frac{1}{4}\right)=\frac{2}{7}\times2=\frac{4}{7}\)