\(=7-\dfrac{2}{5}+\dfrac{1}{3}-6+\dfrac{4}{3}-\dfrac{6}{5}-2+\dfrac{8}{5}-\dfrac{5}{3}\\ =-1\)
e)\(\left(7-\dfrac{2}{5}+\dfrac{1}{3}\right)-\left(6-\dfrac{4}{3}+\dfrac{6}{5}\right)-\left(2-\dfrac{8}{5}+\dfrac{5}{3}\right)\)
=\(\left(\dfrac{7}{1}-\dfrac{2}{5}+\dfrac{1}{3}\right)-\left(\dfrac{6}{1}-\dfrac{4}{3}+\dfrac{6}{5}\right)-\left(\dfrac{2}{1}-\dfrac{8}{5}+\dfrac{5}{3}\right)\)
=\(\left(\dfrac{7.15}{1.15}-\dfrac{2.3}{5.3}+\dfrac{1.5}{3.5}\right)-\left(\dfrac{6.15}{1.15}-\dfrac{4.5}{3.5}+\dfrac{6.3}{5.3}\right)-\left(\dfrac{2.15}{1.15}-\dfrac{8.3}{5.3}+\dfrac{5.5}{3.5}\right)\)
=\(\left(\dfrac{105}{15}-\dfrac{6}{15}+\dfrac{5}{15}\right)-\left(\dfrac{90}{15}-\dfrac{20}{15}+\dfrac{18}{15}\right)-\left(\dfrac{30}{15}-\dfrac{24}{15}+\dfrac{25}{15}\right)\)
=\(\left(\dfrac{105}{15}-\dfrac{6}{15}+\dfrac{5}{15}\right)-\left(\dfrac{90}{15}-\dfrac{20}{15}+\dfrac{18}{15}\right)-\left(\dfrac{30}{15}-\dfrac{24}{15}+\dfrac{25}{15}\right)\)
=\(\dfrac{105}{15}-\dfrac{6}{15}+\dfrac{5}{15}-\dfrac{90}{15}+\dfrac{20}{15}-\dfrac{18}{15}-\dfrac{30}{15}+\dfrac{24}{15}-\dfrac{25}{15_{ }}\)
=\(\dfrac{105-6+5-90+20-18-30+24-25}{15}\)
=-15/15=-1
cho mình đúng đi mình trả lời đầu tiên đấy cả mấy bạn kia nữa
