• Предмет: Математика
  • Автор: Сталкер0987
  • Вопрос задан 8 лет назад

Примеры с решением!!!

Приложения:

Ответы

Ответ дал: zhenyaM2002
0
г) 
 frac{5}{24}  -  frac{1}{60} -  frac{1}{40}  =  frac{5*10 - 1*4 -1*6}{240}=  frac{50-10}{240}= frac{40}{240} = frac{40:40}{240:40} = frac{1}{6}


д) 
 frac{5}{14} + frac{10}{21}  -frac{3}{4} =  frac{5*6}{14*6} + frac{10*4}{21*4} - frac{3*21}{4*21} = \  \ 
= frac{30+40-63}{84} =  frac{70-63}{84} =  frac{7}{84} =  \  \ 
=  frac{7:7}{84:7} =  frac{1}{12}

е)
 frac{5}{6} - frac{3}{16} + frac{5}{12} =  frac{5*8}{6*8} - frac{3*3}{16*3} + frac{5*4}{12*4} = \  \  
=  frac{40 - 9 + 20 }{48} = frac{51}{48}=  frac{51:3}{48:3}=  frac{17}{16}=1 frac{1}{16}

ж)
 (frac{7}{10} + frac{3}{5} ) - ( frac{1}{6}  +frac{2}{3} ) = \  \  
= (frac{7}{10} + frac{3*2}{5*2}) - (  frac{1}{6} + frac{2*2}{3*2} )= \  \ 
=  frac{7+6}{10} -  frac{1+4}{6} =  frac{13}{10} -  frac{5}{6} = \  \  
=  frac{13*3}{10*3} - frac{5*5}{6*5} =  frac{39-25}{30} = \  \  
=  frac{14}{30} =  frac{14 :2}{30:2} = \  \  
= frac{7}{15}

з) 
 frac{2}{3} - ( frac{1}{20} +  frac{2}{9}) - frac{5}{18}= frac{2*60}{3*60} - ( frac{1*9}{20*9} +  frac{2*20}{9*20}) - frac{5*10}{18*10}= \  \ 
=  frac{120}{180} -  frac{9+40}{180} - frac{50}{180} =  frac{120-49-50}{180} =  frac{21}{180} =  frac{21:3}{180:3} =  frac{7}{60}

и)
  frac{1}{3} + frac{1}{4} + frac{1}{5} + frac{1}{6} +  frac{1}{7} =  frac{1*140+1*105+1*84+1*70+1*60}{420} = \  \ 
= frac{459}{420} =   = frac{459:3}{420:3} = frac{153}{140} = 1  frac{13}{140}  \

№2.
в)
  (frac{29}{44}  +  frac{1}{6} ) -  frac{7}{44}  =  frac{29}{44}  +  frac{1}{6}  -  frac{7}{44}  =  frac{29-7}{44}  +  frac{1}{6} =  \  \  
= frac{22}{44} + frac{1}{6} = frac{1}{2} + frac{1}{6} =  frac{1*3+1}{6} = frac{4}{6} = frac{2}{3}

г) 
( frac{5}{18} + frac{19}{36} ) - frac{1}{36} = frac{5}{18} + frac{19}{36}  - frac{1}{36}= frac{5}{18} + frac{19-1}{36} = \  \= frac{5}{18} + frac{18:2}{36:2} =  frac{5+9}{18} =  frac{14}{18} = frac{7}{9}

д)
  frac{35}{68}- (  frac{1}{68} + frac{7}{22} ) =  frac{35}{68}- frac{1}{68}-  frac{7}{22} =  \  \  
= frac{34}{68}- frac{7}{22} =  frac{1}{2} - frac{7}{22} =  frac{1*11-7}{22}= \  \ 
= frac{4}{22} = frac{2}{11}

е)
  frac{14}{39} - ( frac{1}{12} + frac{1}{39} )= frac{14}{39}- frac{1}{12} - frac{1}{39} = frac{14-1}{39} - frac{1}{12} =  frac{13}{39}- frac{1}{12} = \  \ 
=  frac{1}{3}- frac{1}{12} =  frac{4}{12}  -frac{1}{12} =  frac{3}{12} =  frac{1}{4}
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