Решите пожалуста!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

1. Вычислите:
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a)
$\frac{3}{5} + \frac{1}{5} = \frac{3+1}{5} = \frac{4}{5}$
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б)
$\frac{2}{7} + \frac{1}{3} = \frac{6+7}{21} = \frac{13}{21}$
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в)
$\frac{3}{4} + \frac{5}{12} = \frac{9+5}{12} = \frac{14}{12} = \frac{7}{6} = 1 \frac{1}{6}$
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г)
$\frac{2}{25} + \frac{1}{20} = \frac{125+4}{100} = \frac{25+4}{4} = \frac{29}{1} = 29$
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д)
$\frac{3}{2} - \frac{2}{7} = \frac{21-4}{14} = \frac{21-2}{7} = \frac{3-2}{1} = \frac{1}{1} =1$
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е)
$\frac{11}{12} - \frac{2}{3} = \frac{11-8}{12} = \frac{11-2}{3} = \frac{9}{3}= \frac{3}{1} =3$
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ж)
$\frac{2}{3} - \frac{5}{9} = \frac{2-15}{9} = \frac{2-5}{3} = \frac{-3}{3} = -1$
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з)
$\frac{5}{21} - \frac{3}{14} = \frac{70-63}{294} = \frac{7}{294} = \frac{1}{42}$
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2. Вычислите:
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а)
$\frac{2}{15} + ( \frac{1}{15} + \frac{1}{3} ) = 1 \frac{1}{3}$
$\frac{1}{15} + \frac{1}{3} = \frac{1+5}{15} = \frac{1+1}{3} = \frac{2}{3}$ $\frac{2}{15} + \frac{2}{3} = \frac{2+10}{15} = \frac{2+2}{3} = \frac{4}{3} = 1 \frac{1}{3}$
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б)
$\frac{1}{20} + \frac{2}{15} + \frac{3}{20} + \frac{1}{15} = \frac{15+40+45+20}{300} = \frac{120}{300} = \frac{4}{10} = \frac{2}{5}$
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в)
$\frac{3}{4} + \frac{2}{3} - \frac{17}{12} = \frac{9+8-17}{12} = \frac{0}{12} = 0$