вправа 1049 гдз 7 клас алгебра Мерзляк Полонський
7 клас ➠ алгебра ➠ Мерзляк Полонський
Вправа 1049
Відповідь:
\begin{equation}1)\left\{\begin{matrix}
x-3y=5,\\4x+9y=41;
\end{matrix}\right.
\end{equation}
\begin{equation}+\left\{\begin{matrix}
3x-9y=15,\\4x+9y=41;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
3y=x-5,\\7x=56;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
3y=3,\\x=8;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
y=1,\\x=8;
\end{matrix}\right.
\end{equation}
\begin{equation}2)\left\{\begin{matrix}
10x+2y=12,\\-5x+4y=-6;
\end{matrix}\right.
\end{equation}
\begin{equation}+\left\{\begin{matrix}
10x+2y=12,\\-10x+8y=-12;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
10y=0,\\10x=12-2y;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
y=0,\\x=1,2;
\end{matrix}\right.
\end{equation}
\begin{equation}3)\left\{\begin{matrix}
3x-2y=1,\\12x+7y=-26;
\end{matrix}\right.
\end{equation}
\begin{equation}-\left\{\begin{matrix}
12x-8y=4,\\12x+7y=-26;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
3x=1+2y,\\15y=-30;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
3x=-3,\\y=-2;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
x=-1,\\y=-2;
\end{matrix}\right.
\end{equation}
\begin{equation}4)\left\{\begin{matrix}
3x+8y=13,\\2x-3y=17;
\end{matrix}\right.
\end{equation}
\begin{equation}-\left\{\begin{matrix}
6x+16y=26,\\6x-9y=51;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
25y=-25,\\2x=17+3y;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
y=-1,\\2x=14;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
y=-1,\\x=7;
\end{matrix}\right.
\end{equation}
\begin{equation}5)\left\{\begin{matrix}
3x-4y=16,\\5x+6y=14;
\end{matrix}\right.
\end{equation}
\begin{equation}+\left\{\begin{matrix}
9x-12y=48,\\10x+12y=28;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
19x=76,\\6y=14-5x;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
x=4,\\6y=-6;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
x=4,\\y=-1;
\end{matrix}\right.
\end{equation}
\begin{equation}6)\left\{\begin{matrix}
2x+3y=6,\\3x+5y=8;
\end{matrix}\right.
\end{equation}
\begin{equation}-\left\{\begin{matrix}
6x+9y=18,\\6x+10y=16;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
y=-2,\\2x=6-3y;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
y=-2,\\2x=12;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
y=-2,\\x=6;
\end{matrix}\right.
\end{equation}
\begin{equation}7)\left\{\begin{matrix}
5u-7\upsilon=24,\\7u+6\upsilon=2;
\end{matrix}\right.
\end{equation}
\begin{equation}-\left\{\begin{matrix}
35u-49\upsilon=168,\\35u+30\upsilon=10;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
79\upsilon=-158,\\5u=24+7\upsilon;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
\upsilon=-2,\\5u=10;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
\upsilon=-2,\\u=2;
\end{matrix}\right.
\end{equation}
\begin{equation}8)\left\{\begin{matrix}
0,2x+1,5y=10,\\0,4x-0,3y=0,2;
\end{matrix}\right.
\end{equation}
\begin{equation}-\left\{\begin{matrix}
0,4x+3y=20,\\0,4x-0,3y=0,2;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
3,3y=19,8,\\0,2x=10-1,5y;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
y=6,\\0,2x=1;
\end{matrix}\right.
\end{equation}
\begin{equation}\left\{\begin{matrix}
y=6,\\x=5.
\end{matrix}\right.
\end{equation}