1. Вычислите: 1) 5/6 + (−5/7); 2) 2/21 − 3/7; 3) −17/21 + 9/14; 4) 1/3 − (−1/2); 5) 2 5/12 + (−17 3/8); 6) 17 1/8 − 29; 7) −2 3/5 + (−7 3/10); 8) 4 3/4 − 4 11/12.

Question

Вопрос:

Фото задания: 1. Вычислите: 1) 5/6 + (−5/7); 2) 2/21 − 3/7; 3) −17/21 + 9/14; 4) 1/3 − (−1/2); 5) 2 5/12 + (−17 3/8); 6) 17 1/8 − 29; 7) −2…

1. Вычислите: 1) 5/6 + (−5/7); 2) 2/21 − 3/7; 3) −17/21 + 9/14; 4) 1/3 − (−1/2); 5) 2 5/12 + (−17 3/8); 6) 17 1/8 − 29; 7) −2 3/5 + (−7 3/10); 8) 4 3/4 − 4 11/12.

Accepted Answer

\(\frac{5}{6}-\frac{5}{7}=\frac{35-30}{42}=\frac{5}{42}\).
\(\frac{2}{21}-\frac{3}{7}=\frac{2}{21}-\frac{9}{21}=-\frac{7}{21}=-\frac{1}{3}\).
\(-\frac{17}{21}+\frac{9}{14}=-\frac{34}{42}+\frac{27}{42}=-\frac{7}{42}=-\frac{1}{6}\).
\(\frac{1}{3}+\frac{1}{2}=\frac{2+3}{6}=\frac{5}{6}\).
\(2\frac{5}{12}-17\frac{3}{8}=\frac{29}{12}-\frac{139}{8}=\frac{58-417}{24}=-\frac{359}{24}=-14\frac{23}{24}\).
\(17\frac{1}{8}-29=17\frac{1}{8}-29=-11\frac{7}{8}\).
\(-2\frac{3}{5}-7\frac{3}{10}=-\frac{26}{10}-\frac{73}{10}=-\frac{99}{10}=-9\frac{9}{10}\).
\(4\frac{3}{4}-4\frac{11}{12}=\frac{57}{12}-\frac{59}{12}=-\frac{2}{12}=-\frac{1}{6}\).

Ответ: 1) \(\frac{5}{42}\); 2) \(-\frac{1}{3}\); 3) \(-\frac{1}{6}\); 4) \(\frac{5}{6}\); 5) \(-14\frac{23}{24}\); 6) \(-11\frac{7}{8}\); 7) \(-9\frac{9}{10}\); 8) \(-\frac{1}{6}\).