вправа 1036 гдз 7 клас алгебра Мерзляк Полонський
7 клас ➠ алгебра ➠ Мерзляк Полонський
Вправа 1036
Відповідь:
\begin{equation}1)\left\{\begin{matrix}
4x-3y=15,\\ 3x-4y=6;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
x=\frac{3y+15}{4},\\ \frac{3\left ( 3y+15 \right )}{4}-\frac{16y}{4}=\frac{24}{4};
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
x=\frac{3y+15}{4},\\9y+45-16y=24;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
x=\frac{3y+15}{4},\\ -7y=-21;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
x=6,\\y=3;
\end{matrix}\right.
\end{equation}
\begin{equation}2)\left\{\begin{matrix}
2x-3y=2,\\ 5x+2y=24;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
x=\frac{2+3y}{2},\\ \frac{5\left ( 2+3y \right )}{2}+\frac{4y}{2}=\frac{48}{2};
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
x=\frac{2+3y}{2},\\10+15y+4y=48;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
x=\frac{2+3y}{2},\\ 19y=38;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
x=4,\\y=2;
\end{matrix}\right.
\end{equation}
\begin{equation}3)\left\{\begin{matrix}
5y-6x=4,\\ 7x-4y=-1;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
y=\frac{6x+4}{5},\\ \frac{35x}{5}-\frac{4\left ( 6x+4 \right )}{5}=-\frac{5}{5};
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
y=\frac{6x+4}{5},\\35x-24x-16=-5;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
y=\frac{6x+4}{5},\\ 11x=11;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
y=2,\\x=1;
\end{matrix}\right.
\end{equation}
\begin{equation}4)\left\{\begin{matrix}
4x+5y=1,\\ 8x-2y=38;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
4x+5y=1,\\ 4x-y=19;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
4x+5\left ( 4x-19 \right )=1,\\ y=4x-19;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
4x+20x-95=1,\\ y=4x-19;;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
24x=96,\\ y=4x-19;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
x=4,\\ y=-3;
\end{matrix}\right.
\end{equation}
\begin{equation}5)\left\{\begin{matrix}
5a-4b=3,\\ 2a-3b=11;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
\frac{5\left ( 3b+11 \right )}{2}-\frac{8b}{2}=\frac{6}{2},\\a=\frac{3b+11}{2};
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
15b+55-8b=6,\\ a=\frac{3b+11}{2};
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
7b=-49,\\ a=\frac{3b+11}{2};
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
b=-7,\\ a=-5;
\end{matrix}\right.
\end{equation}
\begin{equation}6)\left\{\begin{matrix}
8m-2n=11,\\ 9m+4n=8;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
n=\frac{8m-11}{2},\\ 9m+2\left ( 8m-11 \right )=8;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
n=\frac{8m-11}{2},\\ 9m+16m-22=8;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
n=\frac{8m-11}{2},\\ 25m=30;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
n=-0,7,\\ m=1,2.
\end{matrix}\right.
\end{equation}