Question

3/20+7/30+2/40=???
3/20+7/30+9/50=???
7/40+11/70+13/30=???

Answer 1

Пошаговое объяснение:

$\frac{3}{20} +\frac{7}{30} +\frac{2}{40}=\frac{13}{30}$

$\frac{3}{20} +\frac{7}{30} =\frac{9}{60} +\frac{14}{60} =\frac{23}{60} \\$

$\frac{23}{60} +\frac{2}{40} =\frac{46}{120} +\frac{6}{120} =\frac{52}{120} =\frac{13}{30}$

$\frac{3}{20} +\frac{7}{30} +\frac{9}{50}=\frac{169}{300}$

$\frac{3}{20} +\frac{7}{30} =\frac{9}{60} +\frac{14}{60} =\frac{23}{60}$

$\frac{23}{60} +\frac{9}{50} =\frac{115}{300} +\frac{54}{300} =\frac{169}{300}$

$\frac{7}{40} +\frac{11}{70} +\frac{13}{30}=\frac{643}{840}$

$\frac{7}{40} +\frac{11}{70} =\frac{49}{280} +\frac{44}{280} =\frac{93}{280}$

$\frac{93}{280} +\frac{13}{30} =\frac{279}{840} +\frac{364}{840} =\frac{643}{840}$