вправа 1051 гдз 7 клас алгебра Мерзляк Полонський
7 клас ➠ алгебра ➠ Мерзляк Полонський
Вправа 1051
Відповідь:
\begin{equation}1)\left\{\begin{matrix}
2\left ( 4x-5 \right )-3\left ( 3+4y \right )=5,\\7\left ( 6y-1 \right )-\left ( 4+3x \right )=21y-86;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
8x-10-9-12y=5,\\42y-7-4-3x=21y-86;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
8x-12y=24,\\21y-3x=-75;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
2x-3y=6,\\7y-x=-25;
\end{matrix}\right.
\end{equation}
\begin{equation}+\left\{\begin{matrix}
2x-3y=6,\\14y-2x=-50;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
11y=-44,\\x=25+7y;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
y=-4,\\x=-3;
\end{matrix}\right.
\end{equation}
\begin{equation}2)\left\{\begin{matrix}
-2\left ( 2x+1 \right )+2,5=3\left ( y+2 \right )-8x,\\8-5\left ( 4-x \right )=6y-\left ( 5-x \right );
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
-4x-2+2,5=3y+6-8x,\\8-20+5x=6y-5+x;
\end{matrix}\right.
\end{equation}
\begin{equation}-\left\{\begin{matrix}
4x-3y=5,5,\\4x-6y=7;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
3y=-1,5,\\4x=7+6y;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
y=-0,5,\\x=1;
\end{matrix}\right.
\end{equation}
\begin{equation}3)\left\{\begin{matrix}
\frac{x}{2}-\frac{y}{3}=3,\\\frac{3x}{4}+\frac{5y}{6}=4;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
3x-2y=18,\\9x+10y=48;
\end{matrix}\right.
\end{equation}
\begin{equation}-\left\{\begin{matrix}
9x-6y=54,\\9x+10y=48;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
3x=18+2y,\\16y=-6;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
3x=\frac{69}{4},\\y=-\frac{3}{8};
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
x=5\frac{3}{4},\\y=-\frac{3}{8};
\end{matrix}\right.
\end{equation}
\begin{equation}4)\left\{\begin{matrix}
\frac{x+2}{6}-\frac{y-3}{15}=1,\\\frac{x+2,5}{9}-\frac{y+3}{6}=\frac{1}{3};
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
5\left ( x+2 \right )-2\left ( y-3 \right )=30,\\2\left ( x+2,5 \right )-3\left ( y+3 \right )=6;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
5x+10-2y+6=30,\\2x+5-3y-9=6;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
5x-2y=14,\\2x-3y=10;
\end{matrix}\right.
\end{equation}
\begin{equation}+\left\{\begin{matrix}
15x-6y=42,\\-4x+6y=-20;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
11x=22,\\y=\frac{2x-10}{3};;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
x=2,\\y=-2.
\end{matrix}\right.
\end{equation}