《2025年全效学习同步学练测七年级数学上册湘教版》

1. [2025 广州模拟]解方程组：$\left\{\begin{array}{l} 3x-y=7,\\ y=5-x.\end{array}\right.$

答案： 1. $\begin{cases}x = 3,\\y = 2.\end{cases}$

2. 解方程组：$\left\{\begin{array}{l} 3x-4y=10,\\ x+3y=12.\end{array}\right.$

答案： 2. $\begin{cases}x = 6,\\y = 2.\end{cases}$

3. 解下列方程组：
(1)$\left\{\begin{array}{l} x-3y=10,①\\ 4x+3y=15;②\end{array}\right.$
(2)$\left\{\begin{array}{l} 3x+4y=5,①\\ 5x-2y=17;②\end{array}\right.$
(3)$\left\{\begin{array}{l} 5x-6y=9,①\\ 7x-4y=-5.②\end{array}\right.$

答案： 3.
(1)$\begin{cases}x = 5,\\y = -\frac{5}{3}.\end{cases}$
(2)$\begin{cases}x = 3,\\y = -1.\end{cases}$
(3)$\begin{cases}x = -3,\\y = -4.\end{cases}$

4. 解方程组：$\left\{\begin{array}{l} 3x-4(x-2y)=5,①\\ x-2y=1.②\end{array}\right.$

答案： 4.$\begin{cases}x = 3,\\y = 1.\end{cases}$

5. 解方程组：$\left\{\begin{array}{l} \frac {x+1}{3}=2y,①\\ 2(x+1)-y=11.②\end{array}\right.$

答案： 5.$\begin{cases}x = 5,\\y = 1.\end{cases}$