\(\dfrac{-11}{31}\cdot\dfrac{-2}{17}+\dfrac{7}{31}\cdot\dfrac{-20}{17}-\dfrac{9}{17}\cdot\dfrac{11}{31}\)
\(Q=\dfrac{5}{11}\cdot\dfrac{2}{17}+\dfrac{7}{17}\cdot\dfrac{-6}{11}-\dfrac{9}{17}\cdot\dfrac{5}{11}\)
\(Q=\dfrac{5}{11}.\dfrac{2}{17}+\dfrac{7}{17}.\dfrac{-6}{11}-\dfrac{9}{17}.\dfrac{5}{11}\)
\(Q=\dfrac{5}{11}\left(\dfrac{2}{17}-\dfrac{9}{17}\right)+\dfrac{7}{17}.\dfrac{-6}{11}\)
\(Q=\dfrac{5}{11}.\dfrac{-7}{17}+\dfrac{-7}{17}.\dfrac{6}{11}\)
\(Q=\dfrac{-7}{17}.\left(\dfrac{5}{11}+\dfrac{6}{11}\right)\)
\(Q=\dfrac{-7}{17}\)
e)\(\dfrac{7}{10}\cdot\dfrac{-3}{5}+\dfrac{7}{10}\cdot\dfrac{-2}{5}-\dfrac{3}{10}\)
f)\(\dfrac{-3}{7}\cdot\dfrac{5}{9}+\dfrac{4}{9}\cdot\dfrac{-3}{7}+2\dfrac{3}{7}\)
g)
\(\dfrac{5}{9}\cdot\dfrac{10}{17}+\dfrac{5}{9}\cdot\dfrac{9}{17}-\dfrac{5}{9}\cdot\dfrac{2}{17}\)
Mn giúp em với ạ
\(e.\dfrac{7}{10}\cdot\dfrac{-3}{5}+\dfrac{7}{10}\cdot\dfrac{-2}{5}-\dfrac{3}{10}\)
\(=\dfrac{7}{10}\cdot\left[\left(\dfrac{-3}{5}\right)+\left(\dfrac{-2}{5}\right)\right]-\dfrac{3}{10}\)
\(=\dfrac{7}{10}\cdot1-\dfrac{3}{10}=\dfrac{4}{10}=\dfrac{2}{5}\)
\(f.\dfrac{-3}{7}\cdot\dfrac{5}{9}+\dfrac{4}{9}\cdot\dfrac{-3}{7}+2\dfrac{3}{7}\)
\(=\dfrac{-3}{7}\cdot\left(\dfrac{5}{9}+\dfrac{4}{9}\right)+\dfrac{17}{3}\)
\(=\dfrac{-3}{7}\cdot1+\dfrac{17}{3}=\dfrac{-9}{21}+\dfrac{119}{21}=\dfrac{110}{21}\)
\(g.\dfrac{5}{9}\cdot\dfrac{10}{17}+\dfrac{5}{9}\cdot\dfrac{9}{17}-\dfrac{5}{9}\cdot\dfrac{2}{17}\)
\(=\dfrac{5}{9}\cdot\left(\dfrac{10}{17}+\dfrac{9}{17}-\dfrac{2}{17}\right)\)
\(=\dfrac{5}{9}\cdot1=\dfrac{5}{9}\)
Tính hợp lý:
\(a.\dfrac{3}{17}+\dfrac{-5}{13}+\dfrac{-18}{35}+\dfrac{14}{17}+\dfrac{17}{-35}+\dfrac{-8}{13}\)
\(b.\dfrac{-3}{8}\cdot\dfrac{1}{6}+\dfrac{3}{-8}\cdot\dfrac{5}{6}+\dfrac{-10}{16}\)
\(c.\dfrac{-4}{11}\cdot\dfrac{5}{15}\cdot\dfrac{11}{-4}\)
a: \(=\left(\dfrac{3}{17}+\dfrac{14}{17}\right)+\left(\dfrac{-5}{13}-\dfrac{8}{13}\right)+\left(\dfrac{-18}{35}-\dfrac{17}{35}\right)\)
=1-1-1
=-1
b: \(=\dfrac{-3}{8}\left(\dfrac{1}{6}+\dfrac{5}{6}\right)+\dfrac{-5}{8}=\dfrac{-3}{8}-\dfrac{5}{8}=-1\)
c: \(=\dfrac{4}{4}\cdot\dfrac{5}{15}\cdot\dfrac{11}{11}=\dfrac{1}{3}\)
a) \(=\left(\dfrac{3}{17}+\dfrac{14}{17}\right)+\left(-\dfrac{5}{13}+-\dfrac{8}{13}\right)+\left(-\dfrac{18}{35}+-\dfrac{17}{35}\right)=1+-1+-1=-1\)
b) \(=-\dfrac{3}{8}\cdot\left(\dfrac{1}{6}+\dfrac{5}{6}\right)-\dfrac{10}{16}=-\dfrac{3}{8}-\dfrac{10}{16}=-1\)
c) \(=\left(-\dfrac{4}{11}\cdot-\dfrac{11}{4}\right)\cdot\dfrac{5}{15}=1\cdot\dfrac{1}{3}=\dfrac{1}{3}\)
a)\(=\left(-\dfrac{5}{13}+\dfrac{-8}{13}\right)+\left(-\dfrac{18}{35}-\dfrac{17}{35}\right)+\left(\dfrac{3}{14}+\dfrac{14}{17}\right)=-1-1+1=-1\)
b)\(=\dfrac{-3}{8}.\left(\dfrac{1}{6}+\dfrac{5}{6}\right)-\dfrac{10}{16}=-\dfrac{3}{8}.1-\dfrac{10}{16}=-\dfrac{6}{16}-\dfrac{10}{16}=-\dfrac{16}{16}=-1\)
c)\(\dfrac{-4.5.11}{11.5.3.-4}=\dfrac{1}{3}\)
Tìm x ϵ Z, biết:
\(\dfrac{5}{17}\)+\(\dfrac{-4}{9}\)+-\(\dfrac{20}{31}\)+\(\dfrac{12}{17}\)+\(\dfrac{-11}{-31}\)< \(\dfrac{x}{9}\) ≤ \(\dfrac{-3}{7}\)+\(\dfrac{7}{15}\)+\(\dfrac{4}{-7}\)+\(\dfrac{8}{15}\)+\(\dfrac{2}{3}\)
\(\Leftrightarrow-\dfrac{16}{279}< \dfrac{x}{9}< =\dfrac{2}{3}\)
\(\Leftrightarrow\dfrac{x}{9}=0\)
hay x=0
\(\left(\dfrac{-4}{13}-\dfrac{17}{19}\right):\left(\dfrac{-31}{32}\right)+\left(\dfrac{-9}{13}+\dfrac{2}{19}\right):\dfrac{-33}{31}\)
\(\left(\dfrac{-3}{8}+\dfrac{5}{9}:\dfrac{-11}{37}\right).\left(\dfrac{33}{19}-\dfrac{7}{22}\cdot\dfrac{43}{17}\right).\left(2-\dfrac{7}{13}\cdot\dfrac{7}{26}\right)\)
Mn giúp mk đi mk cần gấp lắm làm ơn !
Tính:
a) \(\dfrac{17}{8}:\left(\dfrac{27}{8}+\dfrac{11}{2}\right);\)
b) \(\dfrac{28}{15}\cdot\dfrac{1}{4^2}.3+\left(\dfrac{8}{15}-\dfrac{69}{60}\cdot\dfrac{5}{23}\right):\dfrac{51}{54}.\)
\(a.\)
\(\dfrac{17}{8}:\left(\dfrac{27}{8}+\dfrac{11}{2}\right)\)
\(=\dfrac{17}{8}:\left(\dfrac{27+44}{8}\right)=\dfrac{17}{8}:\dfrac{71}{8}=\dfrac{17}{8}\cdot\dfrac{8}{71}=\dfrac{17}{71}\)
\(b.\)
\(\dfrac{28}{15}\cdot\dfrac{1}{4^2}\cdot3+\left(\dfrac{8}{15}-\dfrac{69}{60}\cdot\dfrac{5}{23}\right):\dfrac{51}{54}\)
\(=\dfrac{28}{15}\cdot\dfrac{1}{4^2}\cdot3+\left(\dfrac{8}{15}-\dfrac{1}{4}\right):\dfrac{51}{54}\)
\(=\dfrac{28}{15}\cdot\dfrac{1}{4^2}\cdot3+\left(\dfrac{8\cdot4-15}{60}\right):\dfrac{51}{54}\)
\(=\dfrac{28}{15}\cdot\dfrac{1}{4^2}\cdot3+\dfrac{17}{60}:\dfrac{51}{54}\)
\(=\dfrac{28}{15}\cdot\dfrac{1}{16}\cdot3+\dfrac{17}{60}\cdot\dfrac{54}{51}\)
\(=\dfrac{7}{20}+\dfrac{3}{10}\)
\(=\dfrac{7+3\cdot2}{20}=\dfrac{13}{20}\)
a) \(\dfrac{-3}{17}\left(\dfrac{2}{3}+\dfrac{3}{17}\right)\)
b) \(D=\dfrac{-3}{31}+\dfrac{-6}{17}+\dfrac{1}{25}+\dfrac{-28}{31}+\dfrac{-11}{17}+\dfrac{-1}{5}\)
b: D=(-3/31-28/31)+(-6/17-11/17)+(1/25-5/25)
=-2-4/25=-54/25
\(\dfrac{1}{4}\cdot\dfrac{2}{6}\cdot\dfrac{3}{8}\cdot\dfrac{4}{10}\cdot\dfrac{5}{12}..........\cdot\dfrac{30}{62}\cdot\dfrac{31}{64}=2\)x
\(\dfrac{-3}{31}\) +\(\dfrac{-6}{17}\)+\(\dfrac{1}{25}\)+\(\dfrac{-28}{31}\)+\(\dfrac{-11}{17}\)+\(\dfrac{-1}{5}\)
\(=\left[\left(-\dfrac{3}{31}\right)+\left(-\dfrac{28}{31}\right)\right]+\left[\left(-\dfrac{6}{17}\right)+\left(-\dfrac{11}{17}\right)\right]+\left[\dfrac{1}{25}+\left(-\dfrac{1}{5}\right)\right]\)
\(=\left(-1\right)+\left(-1\right)+\left[\dfrac{1}{25}+\left(-\dfrac{5}{25}\right)\right]\)
\(=\left(-1\right)+\left(-1\right)+\left(-\dfrac{4}{25}\right)\)
\(=\left(-2\right)+\left(-\dfrac{4}{25}\right)\)
\(=\left(-\dfrac{50}{25}\right)+\left(-\dfrac{4}{25}\right)\)
\(=-\dfrac{54}{25}\)
\(=\left(\dfrac{-3}{31}+\dfrac{-28}{31}\right)+\left(\dfrac{-6}{17}+\dfrac{-11}{17}\right)+\left(\dfrac{1}{25}+\dfrac{1}{5}\right)\)
\(=-1+-1+\left(\dfrac{1}{25}+\dfrac{-5}{25}\right)\)
\(=-2\)\(+\dfrac{-4}{25}\)
\(=\)\(\dfrac{50}{25}+\dfrac{-4}{25}\)
=\(\dfrac{46}{25}\)