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-2/3 + 1/5. -10/7
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\(\dfrac{4}{5}\)+\(\dfrac{-5}{4}\)=\(\dfrac{0}{4}\)
\(\dfrac{-1}{3}\)+\(\dfrac{2}{5}-\dfrac{5}{6}\)=\(\dfrac{-10}{30}+\dfrac{12}{30}-\dfrac{25}{30}\)=\(\dfrac{-23}{30}\)
\(\dfrac{2}{3}-\dfrac{5}{7}.\dfrac{14}{25}\)=\(\dfrac{2}{3}-\dfrac{2}{5}\)=\(\dfrac{10}{15}-\dfrac{6}{15}\)=\(\dfrac{4}{15}\)
\(=\dfrac{-3}{5}:\dfrac{7}{5}-\dfrac{3}{5}:\dfrac{7}{5}+2\dfrac{3}{5}\)
\(=-\dfrac{6}{5}\times\dfrac{5}{7}+\dfrac{13}{5}=\dfrac{61}{35}\)
a) \(=\left(13\dfrac{2}{7}+2\dfrac{5}{7}\right):\left(-\dfrac{8}{9}\right)\)
\(=16:\dfrac{-8}{9}=\dfrac{-8\cdot\left(-2\right)\cdot9}{-8}=-18\)
b)
\(=\left(\dfrac{-6}{11}\cdot\dfrac{11}{-6}\right)\cdot\dfrac{7\cdot10\cdot\left(-2\right)}{10}\)
\(=-14\)
c) \(=\dfrac{-1}{2}\cdot\dfrac{4}{3}\cdot\dfrac{-7}{2}\)
\(=\dfrac{-1\cdot2\cdot2\cdot\left(-7\right)}{2\cdot3\cdot2}=\dfrac{7}{3}\)
\(a.\left[-\dfrac{6}{11}.\dfrac{11}{-6}\right].\dfrac{7}{10}.\left(-20\right)=1.7.\left(-2\right)=-14\)
\(b.\dfrac{-1}{2}:\dfrac{3}{4}.\dfrac{-7}{2}=\dfrac{7}{4}:\dfrac{3}{4}=\dfrac{7}{3}\)
\(c.\dfrac{93}{7}:-\dfrac{8}{9}+\dfrac{19}{7}:\dfrac{-8}{9}=\left(\dfrac{93}{7}+\dfrac{19}{7}\right):-\dfrac{8}{9}=\dfrac{-9}{8}.\dfrac{112}{7}=-18\)
6/7+(5/8-3/16):5.-4
=6/7+(10/16-3/16):5.-4
=6/7+7/16:5.-4
=6/7+7/80.-4
=6/7+-28/80
=6/7+7/20
120/140+49/140
=169/140
\(-\frac{3}{5}.\frac{11}{7}+\frac{3}{-5}.\frac{4}{7}+\frac{23}{7}\)
\(=\frac{-3}{5}\left(\frac{11}{7}+\frac{4}{7}\right)+\frac{23}{7}\)
\(=\frac{-3}{5}.\frac{15}{7}+\frac{23}{7}\)
\(=\frac{-9}{7}+\frac{23}{7}=2\)
1: 0,35*12,4=0,35*2,4+0,35*10=3,5+0,84=4,34
2: =0,1-2,34=-2,24
3: =5-2,9=2,1
4: \(=2,5\left(10,124-0,124\right)=10\cdot2,5=25\)
5: =-3/7+1/13
=-39/91+7/91
=-32/91
6: =-1/3+1/3=0
\(-\frac{2}{3}+\frac{1}{5}.\frac{-10}{7}\\ =-\frac{2}{3}+\frac{1.-10}{5.7}\\ =-\frac{2}{3}+\frac{-2}{7}\\ =-\frac{14}{21}+\frac{-6}{21}\\ =-\frac{20}{21}\)
=\(\frac{-2}{3}+\frac{1}{5}.\frac{-10}{7}\)
=\(\frac{-2}{3}+\frac{-2}{7}\)
=\(\frac{-20}{21}\)