来源:学生作业帮 编辑:作业帮 分类:数学作业 时间:2024/09/13 14:21:28
如何解同解方程~说方法~最好可以举例子
举例
-2x + 3y = 8 --------------------(1)
3x - y = -5 --------------------(2)
3*(2)==>
9x - 3y = -15 -----------------(3)
(1)+(3) ==>
7x = -7
x = -1 ------------------------------(4)
(1),(4) ==>
-2(-1) + 3y = 8
2 + 3y = 8
3y = 6
y = 2