解方程组.2x+3y/2=3x+2y/5+2 3(2x+3y)/2=2(3x+2y)+6..
问题描述:
解方程组.2x+3y/2=3x+2y/5+2 3(2x+3y)/2=2(3x+2y)+6
..
答
2x+3y/2=3x+2y/5+2
两边同乘以10
20x+15y=30x+4y+20
11y-10x-20=0...........(1)
3(2x+3y)/2=2(3x+2y)+6
3(2x+3y)=4(3x+2y)+12
6x+9y=12x+8y+12
y-6x-12=0.................(2)
由(1)(2)得
x=7, y=54
答
2x+3y/2=3x+2y/5+2整理后为10x-11y+2=0.........A
3(2x+3y)/2=2(3x+2y)+6整理为6x-y+12=0...........B
B×11-A得:56x+112=0,x=-2
y=0
答
2x+3y/2=3x+2y/5+2 ①3(2x+3y)/2=2(3x+2y)+6 ②①式化简得:10x-11y=-20 ③②式化简得:6x-y=-12 ④由④得:y=6x+12 ⑤将⑤代入③得:10x-11(6x+12)=-20x=-2y=6x+12=-12+12=0所以,原方程组的解为x=-2,y=0...