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2. 解方程组$\left\{\begin{array}{l} 2x-y= 5,\\ 4x+3y= -10.\end{array} \right.$
$\begin{cases}2x - y = 5,①\\4x + 3y = -10.②\end{cases}$
①×3+②,得 $10x = 5$. 解得 $x = \frac{1}{2}$.
把 $x = \frac{1}{2}$ 代入①,得 $2×\frac{1}{2} - y = 5$.
解得 $y = -4$.
∴ 原方程组的解为 $\begin{cases}x = \frac{1}{2},\\y = -4.\end{cases}$
$\begin{cases}2x - y = 5,①\\4x + 3y = -10.②\end{cases}$
①×3+②,得 $10x = 5$. 解得 $x = \frac{1}{2}$.
把 $x = \frac{1}{2}$ 代入①,得 $2×\frac{1}{2} - y = 5$.
解得 $y = -4$.
∴ 原方程组的解为 $\begin{cases}x = \frac{1}{2},\\y = -4.\end{cases}$
答案：
2. $\begin{cases}2x - y = 5,①\\4x + 3y = -10.②\end{cases}$
①×3+②,得 $10x = 5$. 解得 $x = \frac{1}{2}$.
把 $x = \frac{1}{2}$ 代入①,得 $2×\frac{1}{2} - y = 5$.
解得 $y = -4$.
∴ 原方程组的解为 $\begin{cases}x = \frac{1}{2},\\y = -4.\end{cases}$
①×3+②,得 $10x = 5$. 解得 $x = \frac{1}{2}$.
把 $x = \frac{1}{2}$ 代入①,得 $2×\frac{1}{2} - y = 5$.
解得 $y = -4$.
∴ 原方程组的解为 $\begin{cases}x = \frac{1}{2},\\y = -4.\end{cases}$
3. 解方程组$\left\{\begin{array}{l} 3x-5y= 3,\\ \frac {x}{2}-\frac {y}{3}= 1.\end{array} \right.$
原方程组整理,得 $\begin{cases}3x - 5y = 3,①\\3x - 2y = 6.②\end{cases}$
②-①,得 $3y = 3$,即 $y = 1$.
将 $y = 1$ 代入①,得 $x = \frac{8}{3}$.
∴ 原方程组的解为 $\begin{cases}x = \frac{8}{3},\\y = 1.\end{cases}$
原方程组整理,得 $\begin{cases}3x - 5y = 3,①\\3x - 2y = 6.②\end{cases}$
②-①,得 $3y = 3$,即 $y = 1$.
将 $y = 1$ 代入①,得 $x = \frac{8}{3}$.
∴ 原方程组的解为 $\begin{cases}x = \frac{8}{3},\\y = 1.\end{cases}$
答案：
3. 原方程组整理,得 $\begin{cases}3x - 5y = 3,①\\3x - 2y = 6.②\end{cases}$
②-①,得 $3y = 3$,即 $y = 1$.
将 $y = 1$ 代入①,得 $x = \frac{8}{3}$.
∴ 原方程组的解为 $\begin{cases}x = \frac{8}{3},\\y = 1.\end{cases}$
②-①,得 $3y = 3$,即 $y = 1$.
将 $y = 1$ 代入①,得 $x = \frac{8}{3}$.
∴ 原方程组的解为 $\begin{cases}x = \frac{8}{3},\\y = 1.\end{cases}$
4. 解方程组$\left\{\begin{array}{l} \frac {x}{2}-\frac {y+1}{3}= 1,\\ 3x+2y= 10.\end{array} \right.$
解：原方程组可化为 $\begin{cases}3x - 2(y + 1) = 6,\\3x + 2y = 10,\end{cases}$
即 $\begin{cases}3x - 2y = 8,①\\3x + 2y = 10.②\end{cases}$
①+②,得 $6x = 18$,即 $x =$
①-②,得 $-4y = -2$,即 $y =$
∴ 原方程组的解为 $\begin{cases}x =$
解：原方程组可化为 $\begin{cases}3x - 2(y + 1) = 6,\\3x + 2y = 10,\end{cases}$
即 $\begin{cases}3x - 2y = 8,①\\3x + 2y = 10.②\end{cases}$
①+②,得 $6x = 18$,即 $x =$
3
.①-②,得 $-4y = -2$,即 $y =$
$\frac{1}{2}$
.∴ 原方程组的解为 $\begin{cases}x =$
3
,\\y =$$\frac{1}{2}$
.\end{cases}$
答案：
4. 原方程组可化为 $\begin{cases}3x - 2(y + 1) = 6,\\3x + 2y = 10,\end{cases}$
即 $\begin{cases}3x - 2y = 8,①\\3x + 2y = 10.②\end{cases}$
①+②,得 $6x = 18$,即 $x = 3$.
①-②,得 $-4y = -2$,即 $y = \frac{1}{2}$.
∴ 原方程组的解为 $\begin{cases}x = 3,\\y = \frac{1}{2}.\end{cases}$
即 $\begin{cases}3x - 2y = 8,①\\3x + 2y = 10.②\end{cases}$
①+②,得 $6x = 18$,即 $x = 3$.
①-②,得 $-4y = -2$,即 $y = \frac{1}{2}$.
∴ 原方程组的解为 $\begin{cases}x = 3,\\y = \frac{1}{2}.\end{cases}$
5. 解方程组$\left\{\begin{array}{l} 4(x-y-1)= 3(1-y)-2,\\ \frac {x}{2}+\frac {y}{3}= 2.\end{array} \right.$
原方程组可化为 $\begin{cases}4x - y = 5,①\\3x + 2y = 12.②\end{cases}$
①×2+②,得 $11x = 22$.
∴ $x = 2$.
把 $x = 2$ 代入①,得 $y = 3$.
∴ 原方程组的解为 $\begin{cases}x = 2,\\y = 3.\end{cases}$
原方程组可化为 $\begin{cases}4x - y = 5,①\\3x + 2y = 12.②\end{cases}$
①×2+②,得 $11x = 22$.
∴ $x = 2$.
把 $x = 2$ 代入①,得 $y = 3$.
∴ 原方程组的解为 $\begin{cases}x = 2,\\y = 3.\end{cases}$
答案：
5. 原方程组可化为 $\begin{cases}4x - y = 5,①\\3x + 2y = 12.②\end{cases}$
①×2+②,得 $11x = 22$.
∴ $x = 2$.
把 $x = 2$ 代入①,得 $y = 3$.
∴ 原方程组的解为 $\begin{cases}x = 2,\\y = 3.\end{cases}$
①×2+②,得 $11x = 22$.
∴ $x = 2$.
把 $x = 2$ 代入①,得 $y = 3$.
∴ 原方程组的解为 $\begin{cases}x = 2,\\y = 3.\end{cases}$
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