Bài tập cuối chương I

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Tính 

a)\(0,3-\dfrac{4}{9}:\dfrac{4}{3}.\dfrac{6}{5}+1\)

b)(\(\dfrac{-1}{3}\))2-\(\dfrac{3}{8}\):(0,5)3 -\(\dfrac{5}{2}\).(-4)

c) 1+2:\(\left(\dfrac{2}{3}-\dfrac{1}{6}\right).\left(-2,25\right)\)

d)\(\left[\left(\dfrac{1}{4}-0,5\right).2+\dfrac{8}{3}\right]:2\)



 


 

Nguyễn Lê Phước Thịnh
29 tháng 10 2022 lúc 19:40

a: \(=\dfrac{3}{10}-\dfrac{4}{9}\cdot\dfrac{3}{4}\cdot\dfrac{6}{5}+1\)

\(=\dfrac{13}{10}-\dfrac{1}{2}=\dfrac{13}{10}-\dfrac{5}{10}=\dfrac{8}{10}=\dfrac{4}{5}\)

b: \(=\dfrac{1}{9}-\dfrac{3}{8}:\dfrac{1}{8}+\dfrac{5}{2}\cdot4\)

\(=\dfrac{1}{9}+10-3=\dfrac{1}{9}+7=\dfrac{64}{9}\)

c: \(=1+2:\left(\dfrac{4}{6}-\dfrac{1}{6}\right)\cdot\left(-\dfrac{9}{4}\right)\)

\(=1+2:\dfrac{1}{2}\cdot\dfrac{-9}{4}\)

\(=1+2\cdot2\cdot\dfrac{-9}{4}=1-9=-8\)

e: \(=\left[\left(\dfrac{1}{4}-\dfrac{1}{2}\right)\cdot2+\dfrac{8}{3}\right]\cdot\dfrac{1}{2}\)

\(=\left[\left(\dfrac{1}{4}-\dfrac{2}{4}\right)\cdot2+\dfrac{8}{3}\right]\cdot\dfrac{1}{2}\)

\(=\left(-\dfrac{1}{2}+\dfrac{8}{3}\right)\cdot\dfrac{1}{2}\)

\(=\dfrac{-3+16}{6}\cdot\dfrac{1}{2}=\dfrac{13}{6}\cdot\dfrac{1}{2}=\dfrac{13}{12}\)