`4 / 15 . 1 / 3 . 15 / 20`
`= [ 4 . 1 . 15 ] / [ 15 . 3 . 20 ]`
`= [ 4 . 1 . 15 ] / [ 15 . 3 . 4 . 5 ]`
`= 1 / [ 3 . 5 ]`
`= 1 / 15`
\(=\left(\dfrac{4}{15}.\dfrac{15}{20}\right).\dfrac{1}{3}=\dfrac{60}{300}.\dfrac{1}{3}=\dfrac{60}{900}=\dfrac{1}{15}\)
\(=\dfrac{4.1.15}{15.3.5.4}=\dfrac{1}{3.5}=\dfrac{1}{15}\)
= (\(\dfrac{4}{15}.\dfrac{15}{20}\)) . \(\dfrac{1}{3}=\dfrac{60}{300}.\dfrac{1}{3}=\dfrac{60}{900}=\dfrac{1}{15}\) Nếu mik tính sai mong bạn thông cảm nha