Вопрос:
Вычислите: 1) 38/49 − 3/7; 2) 5/7 − 1/2; 3) 8/9 − 2/7; 4) 1/10 − 1/11; 5) 1/2 + 1/8; 6) 1/12 + 1/3; 7) 2/3 + 1/9; 8) 5/6 − 3/5; 9) 7/8 − 1/2; 10) 1/3 + 1/7; 11) 3/5 + 5/6; 12) 8/9 − 7/8.
Ответ:
- \(\frac{38}{49}-\frac{3}{7}=\frac{38}{49}-\frac{21}{49}=\frac{17}{49}\).
- \(\frac{5}{7}-\frac{1}{2}=\frac{10}{14}-\frac{7}{14}=\frac{3}{14}\).
- \(\frac{8}{9}-\frac{2}{7}=\frac{56}{63}-\frac{18}{63}=\frac{38}{63}\).
- \(\frac{1}{10}-\frac{1}{11}=\frac{11}{110}-\frac{10}{110}=\frac{1}{110}\).
- \(\frac{1}{2}+\frac{1}{8}=\frac{4}{8}+\frac{1}{8}=\frac{5}{8}\).
- \(\frac{1}{12}+\frac{1}{3}=\frac{1}{12}+\frac{4}{12}=\frac{5}{12}\).
- \(\frac{2}{3}+\frac{1}{9}=\frac{6}{9}+\frac{1}{9}=\frac{7}{9}\).
- \(\frac{5}{6}-\frac{3}{5}=\frac{25}{30}-\frac{18}{30}=\frac{7}{30}\).
- \(\frac{7}{8}-\frac{1}{2}=\frac{7}{8}-\frac{4}{8}=\frac{3}{8}\).
- \(\frac{1}{3}+\frac{1}{7}=\frac{7}{21}+\frac{3}{21}=\frac{10}{21}\).
- \(\frac{3}{5}+\frac{5}{6}=\frac{18}{30}+\frac{25}{30}=\frac{43}{30}=1\frac{13}{30}\).
- \(\frac{8}{9}-\frac{7}{8}=\frac{64}{72}-\frac{63}{72}=\frac{1}{72}\).