Question

найдите значение вырожение​

Answer 1

Пошаговое объяснение:

1)$-\frac{3}{7}+\frac{2}{21}$$=\frac{-9+2}{21}=\frac{-7}{21}=-\frac{7}{21}=-\frac{1}{3}$

2)$\frac{5}{6}+(-\frac{5}{7})=\frac{5}{6}-\frac{5}{7}=\frac{5}{42}$

3)$-\frac{17}{21}+\frac{9}{14}=\frac{-34+27}{42}=\frac{-7}{42}=-\frac{7}{42}=-\frac{1}{6}$

4)3,9+(-3,9)=0

5)2,77+$(-\frac{1}{4})$=$\frac{277}{100}-\frac{1}{4}=\frac{63}{25}=2\frac{13}{25}$

6)$\frac{1}{3}+(-\frac{1}{2})=\frac{1}{3}-\frac{1}{2}=-\frac{1}{6}$

7)$2\frac{5}{12}+(-17\frac{3}{8})=\frac{29}{12}-17\frac{3}{8}=\frac{29}{12}-\frac{139}{8}=-\frac{359}{24}=-14\frac{23}{24}$

8)-29+17$\frac{1}{8}=$$-29+\frac{137}{8}=-\frac{95}{8}=-11\frac{7}{8}$

9)17+(-1,25)=17-1,25=15,25

10)$-2\frac{3}{5}+(-7\frac{3}{10})=-2\frac{3}{5}-7\frac{3}{10}=-(2\frac{3}{5}+7\frac{3}{10})=-((2+7)+(\frac{3}{5}+\frac{3}{10}))=-(9+\frac{9}{10})=-9\frac{9}{10}$

11)$4\frac{3}{4}+(-4\frac{11}{12})=\frac{19}{4}-4\frac{11}{12}=\frac{19}{4}-\frac{59}{12}=-\frac{1}{6}$