вправа 2 гдз 7 клас алгебра Мерзляк Полонський

Відповідь: \begin{equation}1)\frac{1}{3}+\frac{5}{6}=\frac{1\cdot 2+5\cdot 1}{6}=\end{equation} \begin{equation}=\frac{7}{6}=1\frac{1}{6};\end{equation} \begin{equation}2)\frac{3}{7}-\frac{2}{9}=\frac{3\cdot 9-2\cdot 7}{63}=\end{equation} \begin{equation}=\frac{13}{63};\end{equation} \begin{equation}3)\frac{7}{16}\cdot \frac{8}{35}=\frac{\not{7}}{2\cdot \not{8}}\cdot \frac{\not{8}}{\not{7}\cdot 5}=\frac{1}{10};\end{equation} \begin{equation}4)\frac{4}{9}\cdot 18=\frac{4}{\not{9}}\cdot 2\cdot \not{9}=8;\end{equation} \begin{equation}5)\frac{46}{75}: \frac{23}{45}=\frac{2\cdot \not{23}}{5\cdot \not{15}}\cdot \frac{3\cdot \not{15}}{\not{23}}=\end{equation} \begin{equation}=\frac{6}{5}=1\frac{1}{5};\end{equation} \begin{equation}6)\frac{2}{3}: 4=\frac{2}{3}\cdot \frac{1}{4}=\frac{1}{6};\end{equation} \begin{equation}7)10: \frac{5}{11}=10\cdot \frac{11}{5}=22;\end{equation} \begin{equation}8)2\frac{3}{8}+4\frac{1}{6}=\end{equation} \begin{equation}=6\frac{3\cdot 3+4\cdot 1}{24}=6\frac{13}{24};\end{equation} \begin{equation}9)6-1\frac{3}{5}=\frac{5\cdot 6-1\cdot 8}{5}=\end{equation} \begin{equation}=\frac{30-8}{5}=\frac{22}{5}=4\frac{2}{5};\end{equation} \begin{equation}10)4\frac{2}{7}-1\frac{4}{9}=3\frac{9}{7}-1\frac{4}{9}=\end{equation} \begin{equation}=2\frac{9\cdot 9-4\cdot 7}{63}=2\frac{53}{63};\end{equation} \begin{equation}11)8\frac{3}{4}\cdot 1\frac{3}{14}=\frac{35}{4}\cdot \frac{17}{14}=\end{equation} \begin{equation}=\frac{5\cdot 7}{4}\cdot \frac{17}{2\cdot 7}=\frac{85}{8}=\end{equation} \begin{equation}=10\frac{5}{8};\end{equation} \begin{equation}12)1\frac{3}{5}: 5\frac{1}{3}=\frac{8}{5}: \frac{16}{3}=\end{equation} \begin{equation}=\frac{8}{5}\cdot \frac{3}{16}=\frac{3}{10}.\end{equation}