Решите: а)(2/9+1 2/3)*3 б)5/12*2 3/7+5/12*3 4/7 в)(5 2/9*3 1/8+3 1/3)*3-7 2/3 г)(5 2/9*1,4+3 1/3)*3-7 2/3. Created by Supernaturalfox. matematika-ru

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Ellenochka А) $(\frac{2}{9}+1 \frac{2}{3})*3= \frac{2}{9}*\frac{3}{1} +\frac{5}{3}*\frac{3}{1}=\frac{2}{3}+\frac{5}{1}=5\frac{2}{3}$

б) $\frac{5}{12} *2 \frac{3}{7} + \frac{5}{12} *3 \frac{4}{7} = \frac{5}{12} *6= \frac{5}{2} =2 \frac{1}{2}$

в) $(5 \frac{2}{9} *3 \frac{1}{8} +3 \frac{1}{3} )*3-7 \frac{2}{3} =\frac{47}{9} * \frac{25}{8} *3+ \frac{10}{3}*3-7 \frac{2}{3}= \\ = \frac{1175}{24} +10-7\frac{2}{3}=48\frac{23}{24} + 2 \frac{1}{3} =51 \frac{7}{24}$

г) $(5 \frac{2}{9} *1,4+3 \frac{1}{3} )*3-7 \frac{2}{3} = \frac{47}{9} * \frac{7}{5} *3+ \frac{10}{3} *3-7 \frac{2}{3} = \\ =21 \frac{14}{15} +2 \frac{5}{15} =24 \frac{4}{15}$

1 votes Thanks 2

233334 $4. (5 \frac{2}{9}*1,4+3 \frac{1}{3})*3-7 \frac{2}{3}=24 \frac{4}{15} \\ \\ 
1)5 \frac{2}{9}*1,4=7 \frac{14}{45} \\ \\ 
2) 7\frac{14}{45}+3 \frac{1}{3}=7 \frac{14}{45}+3 \frac{15}{45}=10 \frac{29}{45} \\ \\ 
3) \frac{479}{45}*3=31 \frac{14}{15} \\ \\ 
4) 31 \frac{14}{15}-7\frac{2}{3}=31 \frac{14}{15}-7 \frac{10}{15}=24 \frac{4}{15}$ $1. ( \frac{2}{9}+1 \frac{2}{3})*3= \frac{2}{3}+5=5 \frac{2}{3} \\ \\ 
2. \frac{5}{12}*2 \frac{3}{7}+ \frac{5}{12}*3 \frac{4}{7}= \frac{5}{12}*( 2\frac{3}{7}+3 \frac{4}{7})= \frac{5}{12}*6=2,5 \\ \\ 
3.(5 \frac{2}{9}*3 \frac{1}{8}+3 \frac{1}{3})*3-7 \frac{2}{3}= \\ \\ 
1) \frac{47}{9}* \frac{25}{8}=16 \frac{23}{72} \\ \\ 
2) 16 \frac{23}{72}+3 \frac{1}{3}=19 \frac{47}{72} \\ \\ 
3) 19 \frac{47}{72}*3=58 \frac{23}{24} \\ \\ 
4)58 \frac{23}{24}-7 \frac{2}{3}=51 \frac{7}{24} \\ \\$

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