номер 92 гдз 8 класс алгебра Муравин Муравин

1)\begin{equation}\frac{a}{8}+\frac{3a}{4}=\frac{a+6a}{8}=\frac{7a}{8} \end{equation} 2)\begin{equation}\frac{5c}{6}-\frac{c}{2}=\frac{5c-3c}{6}=\frac{2c}{6}=\frac{c}{3} \end{equation} 3)\begin{equation}\frac{x}{9y}-\frac{2x}{27y}=\frac{3x-2x}{27y}=\frac{x}{27y} \end{equation} 4)\begin{equation}\frac{7b}{12a}+\frac{3b}{4a}=\frac{7b+9b}{12a}=\frac{16b}{12a}=\frac{4b}{3a} \end{equation} 5)\begin{equation}\frac{7c}{6ab}+\frac{2}{3a}=\frac{7c+4b}{6ab} \end{equation} 6)\begin{equation}\frac{11}{5x}-\frac{3y}{15ax}=\frac{33a-3y}{15ax}= \end{equation} \begin{equation}=\frac{3\left ( 11a-y \right )}{15ax}=\frac{11a-y}{5ax} \end{equation} 7)\begin{equation}\frac{a}{bcy}-\frac{b}{acy}=\frac{a^{2}-b^{2}}{abcy} \end{equation} 8)\begin{equation}\frac{y}{abc}+\frac{b}{acy}=\frac{y^{2}+b^{2}}{abcy} \end{equation} 9)\begin{equation}\frac{3b}{2a^{2}}-\frac{5}{4a^{3}}=\frac{6ab-5}{4a^{3}} \end{equation}