{4x+7y+7=3x+2y+4,5x+y+1=6x-1解方程租

分类: 作业答案 • 2021-12-19 12:09:50

问题描述：

答

4x+7y+7=3x+2y+4
x+5y+3=0
x=-5y-3
5x+y+1=6x-1
x-y-2=0
-5y-3-y-2=0
-6y-5=0
y=5/6
x=-43/6

答

由B组得Y=X-2代入A:4X+7(X-2)+7=3X+2(X-2)+4
得出X=7/6;Y=X-2所以Y=-5/6

答

原方程组即为:x+5y=-3,-x+y=-2.相加得6y=-5,y=-5/6,代入得x=7/6