Bạn viết lại đề, (1 và 2/25 + .....)
Bạn sửa phần in đậm.
(\(1\dfrac{2}{25}\) + \(\dfrac{14}{9}\) + \(\dfrac{17}{5}\)) - (\(\dfrac{2}{25}\) + \(\dfrac{5}{9}\) + 40%)
= \(1\dfrac{2}{25}\) + \(\dfrac{14}{9}\) + \(\dfrac{17}{5}\) - \(\dfrac{2}{25}\) - \(\dfrac{5}{9}\) - 40%
= \(1\dfrac{2}{25}\) + \(\dfrac{14}{9}\) + \(\dfrac{17}{5}\) - \(\dfrac{2}{25}\) - \(\dfrac{5}{9}\) - \(\dfrac{2}{5}\)
= (\(1\dfrac{2}{25}\) - \(\dfrac{2}{25}\) ) + (\(\dfrac{14}{9}\) - \(\dfrac{5}{9}\)) + (\(\dfrac{17}{5}\) - \(\dfrac{2}{5}\) )
= 1 + 1 + 3
= 5
\(\left(1\dfrac{2}{25}+\dfrac{14}{9}+\dfrac{17}{5}\right)-\left(\dfrac{2}{25}+\dfrac{5}{9}+40\%\right)\)
\(=\left(1+\dfrac{2}{25}+\dfrac{14}{9}+\dfrac{17}{5}\right)-\left(\dfrac{2}{25}+\dfrac{5}{9}+\dfrac{40}{100}\right)\)
\(=1+\dfrac{2}{25}+\dfrac{14}{9}+\dfrac{17}{5}-\left(\dfrac{2}{25}+\dfrac{5}{9}+\dfrac{2}{5}\right)\)
\(=1+\dfrac{2}{25}+\dfrac{14}{9}+\dfrac{17}{5}-\dfrac{2}{25}-\dfrac{5}{9}-\dfrac{2}{5}\)
\(=1+\left(\dfrac{2}{25}+\dfrac{-2}{25}\right)+\left(\dfrac{14}{9}+\dfrac{-5}{9}\right)+\left(\dfrac{17}{5}+\dfrac{-2}{5}\right)\)
\(=1+0+1+3\)
\(=5\)
