Tính:
A=(3/10-4/15-7/20).(-5/19) trên (1/4+1/7)-(-3/35).4/3
B=1+1/3 trên 1-1/3-1 trên 1+1/3
Những câu hỏi liên quan
(3/10-4/15-7/20).5/19 trên (1/14+1/7+3/35).-4/3
Bạn nào giúp mik giải bài toán này với:
* ( 3/10 - 4/15 - 7/20 ) x 5/19 tất cả trên ( 1/14 + 1/7 - âm 3/35 ) x âm 4/3
*( 1+2+3+...+100) x (1/3 -1/5 -1/7 -1/9) x (6,3 x 12 - 21 x 3,6) tất cả trên 1/2 + 1/3 + 1/4 +....+1/100
*\(\frac{\left(\frac{3}{10}-\frac{4}{15}-\frac{7}{20}\right).\frac{5}{19}}{\left[\frac{1}{14}+\frac{1}{7}-\left(-\frac{3}{35}\right)\right].\frac{4}{3}}=\frac{\left(\frac{18}{60}-\frac{16}{60}-\frac{21}{60}\right).\frac{5}{19}}{\left(\frac{5}{70}+\frac{10}{70}+\frac{6}{70}\right).\frac{4}{3}}=\frac{\frac{-19}{60}.\frac{5}{19}}{\frac{21}{70}.\frac{4}{3}}=\frac{\frac{-1}{12}}{\frac{14}{35}}=-\frac{1}{12}.\frac{35}{14}=\frac{-35}{168}\)
*\(\frac{\left(1+2+3+...+100\right).\left(\frac{1}{3}-\frac{1}{5}-\frac{1}{7}-\frac{1}{9}\right).\left(6,3.12-21.3,6\right)}{\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{100}}\)
=\(\frac{\left(1+2+3+...+100\right)\left(\frac{1}{3}-\frac{1}{5}-\frac{1}{7}-\frac{1}{9}\right).\left(\frac{63}{10}.12-21.\frac{18}{5}\right)}{\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{100}}\)
=\(\frac{\left(1+2+3+...+100\right)\left(\frac{1}{3}-\frac{1}{5}-\frac{1}{7}-\frac{1}{9}\right).\left(\frac{378}{5}-\frac{378}{5}\right)}{\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{100}}\)
=\(\frac{\left(1+2+3+...+100\right)\left(\frac{1}{3}-\frac{1}{5}-\frac{1}{7}-\frac{1}{9}\right).0}{\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{100}}=0\)
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1.
A= (3/10 - 4/15 - 7/20) . 5/19 / [1/14 + 1/7 - (-3/35)] . -4/3
tính
a. 1/100.99 - 1/ 99.98 - 1/98-97 -........- 1/3.2-1/2.1
b . ( 3/10-4/15-7/20).5/19 / ( 1/14+1/7- -3/35 ). -4/3
tính: (9/10-4/15-7/20).5/19/(1/14+1/7+3/35).-4/5
Tính
( 3/10 - 4/15 - 7/20 ) * 5/19
(1/14 + 1/7 + 3/35 ) * -4/3
\(\frac{\left(\frac{3}{10}-\frac{4}{15}-\frac{7}{20}\right)\cdot\frac{5}{19}}{\left(\frac{1}{14}+\frac{1}{7}+\frac{3}{35}\right)\cdot\left(\frac{-4}{3}\right)}=\frac{\left(\frac{18}{60}-\frac{16}{60}-\frac{21}{60}\right)\cdot\frac{5}{19}}{\left(\frac{5}{70}+\frac{10}{70}+\frac{6}{70}\right)\cdot\left(\frac{-4}{3}\right)}=\frac{\left(\frac{-19}{60}\right)\cdot\frac{5}{19}}{\frac{3}{10}\cdot\left(\frac{-4}{3}\right)}\)
\(=\frac{\frac{-1}{12}}{\frac{-2}{5}}=\left(\frac{-1}{12}\right):\left(\frac{-2}{5}\right)=\frac{5}{24}\)
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Tính bằng cách hợp lý :
[(3/10- 4/15 - 7/20).5/19] / {[1/14+1/7- (-3) /35].[(-4)/3]
\(\dfrac{\left[\left(\dfrac{3}{10}-\dfrac{4}{15}-\dfrac{7}{20}\right)\cdot\dfrac{5}{19}\right]}{\left[\dfrac{1}{14}+\dfrac{1}{7}-\dfrac{\left(-3\right)}{35}\right]\cdot\left(-\dfrac{4}{3}\right)}\)
\(=\dfrac{\left(\dfrac{18}{60}-\dfrac{16}{60}-\dfrac{21}{60}\right)\cdot\dfrac{5}{19}}{\left(\dfrac{5}{70}+\dfrac{10}{70}+\dfrac{6}{70}\right)\cdot\dfrac{-4}{3}}=\dfrac{\dfrac{-19}{60}\cdot\dfrac{5}{19}}{\dfrac{21}{70}\cdot\dfrac{-4}{3}}\)
\(=-\dfrac{1}{12}:\dfrac{-2}{5}=\dfrac{1}{12}\cdot\dfrac{5}{2}=\dfrac{5}{24}\)
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(3/10-4/15-7/20)×5/19
-------------------------------------
[1/14+1/7-(-3/35)]×(-4/3)
a)(3/10-4/15-7/20).5/19 / (1/14+1/7-(-3/35)).(-4/3)
b)(1+2+3+...+100).(1/3-1/5-1/7-1/9).(6,3.12-21.3,6) / 1/2+1/3+1/4+...+1/100
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