номер 98 гдз 8 класс алгебра Муравин Муравин

1)\begin{equation}\frac{5a-b}{3a+3b}+\frac{3a+7b}{2a+2b}=\frac{19}{6} \end{equation} \begin{equation}\frac{5a-b}{3\left ( a+b \right )}+\frac{3a+7b}{2\left ( a+b \right )}=\frac{19}{6} \end{equation} \begin{equation}\frac{10a-2b+9a+21b}{6\left ( a+b \right )}= \end{equation} \begin{equation}=\frac{19a+19b}{6\left ( a+b \right )}=\frac{19\left ( a+b \right )}{6\left ( a+b \right )}=\frac{19}{6} \end{equation} \begin{equation}\frac{19}{6}=\frac{19}{6} \end{equation} 2)\begin{equation}\frac{3x+12y}{5x-5y}-\frac{x+11y}{4x-4y}=\frac{7}{20} \end{equation} \begin{equation}\frac{3x+12y}{5\left ( x-y \right )}-\frac{x+11y}{4\left ( x-y \right )}=\frac{7}{20} \end{equation} \begin{equation}\frac{12x+48y-5x-55y}{20\left ( x-y \right )}=\frac{7}{20} \end{equation} \begin{equation}\frac{7x-7y}{20\left ( x-y \right )}=\frac{7\left ( x-y \right )}{20\left ( x-y \right )}=\frac{7}{20} \end{equation} \begin{equation}\frac{7}{20}=\frac{7}{20} \end{equation}