\(\left(\dfrac{1}{5}-\dfrac{9}{10}\right):\dfrac{-5}{4}-\left(\dfrac{1}{5}+1,6\right):\dfrac{-5}{4}\)
= \(\left(\dfrac{1}{5}-\dfrac{9}{10}-\dfrac{1}{5}-1.6\right):\dfrac{-5}{4}\)
= \(\left(-\dfrac{9}{10}-1,6\right):\dfrac{-5}{4}\)
= \(\left(-0.9-1.6\right):\left(-1.25\right)\)
= (-2.5) : (-1.25) = 2
\(\left(\dfrac{1}{5}-\dfrac{9}{10}\right):\left(-\dfrac{5}{4}\right)-\left(\dfrac{1}{5}+1,6\right):\left(-\dfrac{5}{4}\right)\)
\(=\left(\dfrac{1}{5}-\dfrac{9}{10}\right).\left(-\dfrac{4}{5}\right)-\left(\dfrac{1}{5}+1,6\right).\left(-\dfrac{4}{5}\right)\)
\(=\left(-\dfrac{4}{5}\right)\left(\dfrac{1}{5}-\dfrac{9}{10}-\dfrac{1}{5}-1,6\right)\)
\(=-\dfrac{4}{5}.\left(-2,5\right)=2\)
Chúc bạn học tốt!!!
