《2025年新课程同步学案八年级数学上册北师大版》

(1)$\begin{cases}3x + 2y = 14, \\ 3x - 4y = 2;\end{cases}$ (2)$\begin{cases}2x + 3y = 13, \\ 3x + 1 = y + 4;\end{cases}$
(3)$\begin{cases}3(x - 1) = y + 5, \\ 5(y - 1) = 3(x + 5);\end{cases}$ (4)$\begin{cases}5x - y = 4, \\ \dfrac{x}{2} + 1 = \dfrac{y}{3};\end{cases}$
(5)$\begin{cases}\dfrac{m}{3} - \dfrac{n}{4} = 3, \\ \dfrac{m}{2} - \dfrac{n}{3} = 13;\end{cases}$ (6)$\begin{cases}\dfrac{2}{3}x - \dfrac{3}{4}y = \dfrac{1}{2}, \\ 4(x - y) - 3(2x + y) = 17;\end{cases}$
(7)$\begin{cases}3x + 2y = 5x + 2, \\ 2(3x + 2y) = 2x + 8;\end{cases}$ (8)$\begin{cases}3(x + y) + 2(x - y) = 10, \\ \dfrac{x + y}{4} + \dfrac{x - y}{2} = \dfrac{7}{2}。\end{cases}$

答案： （1）$\left\{\begin{array}{l} x=\dfrac {10}{3},\\ y=2\end{array}\right. $（2）$\left\{\begin{array}{l} x=2,\\ y=3\end{array}\right. $（3）$\left\{\begin{array}{l} x=5,\\ y=7\end{array}\right. $（4）$\left\{\begin{array}{l} x=2,\\ y=6\end{array}\right. $（5）$\left\{\begin{array}{l} m=162,\\ n=204\end{array}\right. $（6）$\left\{\begin{array}{l} x=-\dfrac {3}{2},\\ y=-2\end{array}\right. $（7）$\left\{\begin{array}{l} x=\dfrac {1}{2},\\ y=\dfrac {3}{2}\end{array}\right. $（8）$\left\{\begin{array}{l} x=3,\\ y=-5\end{array}\right. $