Câu hỏi của Nguyễn Thị Hạnh

Question

Bài 1. (2 điểm) Tính hợp lí nếu có thể.

a)   $\dfrac{6}{5}+\dfrac{4}{3}.\dfrac{21}{8}-\dfrac{13}{10}$;

b)   $\dfrac{-11}{12}.\dfrac{18}{25}+\dfrac{-11}{12}.\dfrac{7}{25}+\dfrac{11}{12}$;

c)   $12,8...

Nguyễn Lê Phước Thịnh · Accepted Answer

a: $\dfrac{6}{5}+\dfrac{4}{3}\cdot\dfrac{21}{8}-\dfrac{13}{10}$$=\dfrac{12}{10}-\dfrac{13}{10}+\dfrac{4}{8}\cdot\dfrac{21}{3}$$=\dfrac{-1}{10}+\dfrac{7}{2}=\dfrac{-1}{10}+\dfrac{35}{10}=\dfrac{34}{10}=\dfrac{17}{5}$b: $\dfrac{-11}{12}\cdot\dfrac{18}{25}+\dfrac{-11}{12}\cdot\dfrac{7}{25}+\dfrac{11}{12}$$=\dfrac{11}{12}\left(-\dfrac{18}{25}-\dfrac{7}{25}\right)+\dfrac{11}{12}$$=-\dfrac{11}{12}+\dfrac{11}{12}=0$c: $12,89+27,11-43,65+\left(-56,35\right)$$=\left(12,89+27,11\right)-\left(43,65+56,35\right)$=40-100=-60d: $1\dfrac{13}{15}\cdot\left(0,5\right)^2\cdot3+\left(\dfrac{8}{15}-1\dfrac{19}{60}\right):1\dfrac{23}{24}$$=\dfrac{28}{15}\cdot\dfrac{1}{4}\cdot3+\left(\dfrac{32}{60}-\dfrac{79}{60}\right):\dfrac{47}{24}$$=\dfrac{7}{5}+\dfrac{-47}{60}\cdot\dfrac{24}{47}$$=\dfrac{7}{5}-\dfrac{2}{5}=\dfrac{5}{5}=1$Câu trả lời: a: $\dfrac{6}{5}+\dfrac{4}{3}\cdot\dfrac{21}{8}-\dfrac{13}{10}$$=\dfrac{12}{10}-\dfrac{13}{10}+\dfrac{4}{8}\cdot\dfrac{21}{3}$$=\dfrac{-1}{10}+\dfrac{7}{2}=\dfrac{-1}{10}+\dfrac{35}{10}=\dfrac{34}{10}=\dfrac{17}{5}$b: $\dfrac{-11}{12}\cdot\dfrac{18}{25}+\dfrac{-11}{12}\cdot\dfrac{7}{25}+\dfrac{11}{12}$$=\dfrac{11}{12}\left(-\dfrac{18}{25}-\dfrac{7}{25}\right)+\dfrac{11}{12}$$=-\dfrac{11}{12}+\dfrac{11}{12}=0$c: $12,89+27,11-43,65+\left(-56,35\right)$$=\left(12,89+27,11\right)-\left(43,65+56,35\right)$=40-100=-60d: $1\dfrac{13}{15}\cdot\left(0,5\right)^2\cdot3+\left(\dfrac{8}{15}-1\dfrac{19}{60}\right):1\dfrac{23}{24}$$=\dfrac{28}{15}\cdot\dfrac{1}{4}\cdot3+\left(\dfrac{32}{60}-\dfrac{79}{60}\right):\dfrac{47}{24}$$=\dfrac{7}{5}+\dfrac{-47}{60}\cdot\dfrac{24}{47}$$=\dfrac{7}{5}-\dfrac{2}{5}=\dfrac{5}{5}=1$

Lê Minh Long · Answer

a) 65+43.218−1310=65+72−1310=1210+3510−1310=3410=17556​+34​.821​−1013​=56​+27​−1013​=1012​+1035​−1013​=1034​=517​.

b) −1112.1825+−1112.725+1112=−1112.(1825+725−1)=−1112.0=012−11​.2518​+12−11​.257​+1211​=12−11​.(2518​+257​−1)=12−11​.0=0.

c) 12,89−43,65+27,11+(−56,35)12,89−43,65+27,11+(−56,35)

=(12,89+27,11)−(43,65+56,35)=(12,89+27,11)−(43,65+56,35)

=40−100=−60.=40−100=−60.

d) 11315.(0,5)2.3+(815−11960):1232411513​.(0,5)2.3+(158​−16019​):12423​

=2815.14.3+(815−7960):4724=1528​.41​.3+(158​−6079​):2447​

=75+(−4760):4724=57​+(60−47​):2447​

=75+(−25)=57​+(5−2​)

=1=1.Câu trả lời: a) 65+43.218−1310=65+72−1310=1210+3510−1310=3410=17556​+34​.821​−1013​=56​+27​−1013​=1012​+1035​−1013​=1034​=517​.

b) −1112.1825+−1112.725+1112=−1112.(1825+725−1)=−1112.0=012−11​.2518​+12−11​.257​+1211​=12−11​.(2518​+257​−1)=12−11​.0=0.

c) 12,89−43,65+27,11+(−56,35)12,89−43,65+27,11+(−56,35)

=(12,89+27,11)−(43,65+56,35)=(12,89+27,11)−(43,65+56,35)

=40−100=−60.=40−100=−60.

d) 11315.(0,5)2.3+(815−11960):1232411513​.(0,5)2.3+(158​−16019​):12423​

=2815.14.3+(815−7960):4724=1528​.41​.3+(158​−6079​):2447​

=75+(−4760):4724=57​+(60−47​):2447​

=75+(−25)=57​+(5−2​)

=1=1.

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