Question

[Ngân Võ Karry]

Tính hợp lí, tính nhanh( nếu có )

a)\(\dfrac{0,75-0,6+\dfrac{3}{7}+\dfrac{3}{13}}{2,75-2,2+\dfrac{11}{7}+\dfrac{11}{13}}\) c)\(-\left|1,5\right|.(1\dfrac{1}{3}-2)-\left|-\dfrac{2}{3}\right|\)

b)\(\dfrac{0,375-0,3+\dfrac{3}{11}+\dfrac{3}{12}\dfrac{ }{ }}{0.625-0,5+\dfrac{5}{11}+\dfrac{5}{12}}\) d)\([(\dfrac{2}{193}-\dfrac{3}{386}).\dfrac{193}{17}+\dfrac{33}{34}]:[(\dfrac{7}{2001}+\dfrac{11}{4002}.\dfrac{2001}{25}+\dfrac{9}{12}]\)

Answer 1

[thám tử]

a, \(\dfrac{0,75-0,6+\dfrac{3}{7}+\dfrac{3}{13}}{2,72-2,2+\dfrac{11}{7}+\dfrac{11}{13}}\)

= \(\dfrac{\dfrac{3}{4}-\dfrac{3}{5}+\dfrac{3}{7}+\dfrac{3}{13}}{\dfrac{11}{4}-\dfrac{11}{5}+\dfrac{11}{7}+\dfrac{11}{13}}\)

= \(\dfrac{3.\left(\dfrac{1}{4}-\dfrac{1}{5}+\dfrac{1}{7}+\dfrac{1}{13}\right)}{11.\left(\dfrac{1}{4}-\dfrac{1}{5}+\dfrac{1}{7}+\dfrac{1}{13}\right)}\)

= \(\dfrac{3}{11}\)

b. \(\dfrac{0,357-0,3+\dfrac{3}{11}+\dfrac{3}{12}}{0,625-0,5+\dfrac{5}{11}+\dfrac{5}{12}}\)

= \(\dfrac{\dfrac{3}{8}-\dfrac{3}{10}+\dfrac{3}{11}+\dfrac{3}{12}}{\dfrac{5}{8}-\dfrac{5}{10}+\dfrac{5}{11}+\dfrac{5}{12}}\)

= \(\dfrac{3.\left(\dfrac{1}{8}-\dfrac{1}{10}+\dfrac{1}{11}+\dfrac{1}{12}\right)}{5.\left(\dfrac{1}{8}-\dfrac{1}{10}+\dfrac{1}{11}+\dfrac{1}{12}\right)}\)

= \(\dfrac{3}{5}\)

c, \(-\left|-1,5\right|.\left(1\dfrac{1}{3}-2\right)-\left|-\dfrac{2}{3}\right|\)

= \(-1,5.\left(\dfrac{4}{3}-2\right)-\dfrac{2}{3}\)

= \(-1,5.\left(\dfrac{-2}{3}\right)-\dfrac{2}{3}\)

= \(1-\dfrac{2}{3}=\dfrac{1}{3}\)