137 Вправа 137Алгебра 8 клас Бевз 2025 · § 3 · стор. 31

137. Виконай дії.

а) ${\displaystyle 1\frac{2}{3}+\frac{2}{3}=}$${\displaystyle \frac{5}{3}+\frac{2}{3}=}$${\displaystyle \frac{7}{3}=}$${\displaystyle 2\frac{1}{3}}$;

б) ${\displaystyle \frac{2}{3}+\frac{5}{6}=}$${\displaystyle \frac{2\cdot 2}{3\cdot 2}+\frac{5}{6}=}$${\displaystyle \frac{4+5}{6}=}$${\displaystyle \frac{9}{6}=}$${\displaystyle \frac{3}{2}=}$${\displaystyle 1\frac{1}{2}}$;

в) ${\displaystyle 7-\frac{9}{11}=}$${\displaystyle 6\frac{11}{11}-\frac{9}{11}=}$${\displaystyle 6\frac{2}{11}}$;

г) ${\displaystyle \frac{5}{21}-1\frac{1}{35}=}$${\displaystyle \frac{5}{21}-\frac{36}{35}=}$${\displaystyle \frac{5\cdot 5}{105}-\frac{36\cdot 3}{105}}$=

=${\displaystyle \frac{25-108}{105}=}$${\displaystyle -\frac{83}{105}}$.