= \(\left(\dfrac{25}{100}+\dfrac{3}{5}-\dfrac{75}{100}+\dfrac{7}{5}\right):\dfrac{-5}{2}\)
= \(\left(\dfrac{25}{100}+\dfrac{3}{5}_{ }+\dfrac{-75}{100}+\dfrac{7}{5}\right).\dfrac{-2}{5}\)
= \(\left(\dfrac{1}{4}+\dfrac{3}{5}+\dfrac{-3}{4}+\dfrac{7}{5}\right).\dfrac{-2}{5}\)
= \(\left[\left(\dfrac{1}{4}+\dfrac{-3}{4}\right)+\left(\dfrac{3}{5}+\dfrac{7}{5}\right)\right].\dfrac{-2}{5}\)
= \(\left(\dfrac{-2}{4}+\dfrac{10}{5}\right).\dfrac{-2}{5}\)
= \(\left(\dfrac{-10}{20}+\dfrac{40}{20}\right).\dfrac{-2}{5}\)
= \(\dfrac{30}{20}.\dfrac{2}{5}\)
= \(\dfrac{30.2}{20.5}\)
= \(\dfrac{6.1}{10.1}\)
= \(\dfrac{6}{10}=\dfrac{3}{5}\)
= (25100+35−75100+75):−52(25100+35−75100+75):−52
= (25100+35+−75100+75).−25(25100+35+−75100+75).−25
= (14+35+−34+75).−25(14+35+−34+75).−25
= [(14+−34)+(35+75)].−25[(14+−34)+(35+75)].−25
= (−24+105).−25(−24+105).−25
= (−1020+4020).−25(−1020+4020).−25
= 3020.253020.25
= 30.220.530.220.5
= 6.110.16.110.1
= 610=35
- kết quả là \(\dfrac{-3}{5}\)nha tại mình quên dấu (-)
