解方程组1.x-2y=3,x/5-y/2=7/10 2.3(x-1)-4(y-4)=0,5(y-1)=3(x+5)
问题描述：
解方程组1.x-2y=3,x/5-y/2=7/10 2.3(x-1)-4(y-4)=0,5(y-1)=3(x+5)
答
x-2y=3
x/5-y/2=7/10
x-2y=3 (1)
2x-5y=7 (2)
(2)-(1)x2
-y=1
y=-1
x=1
(2)
3(x-1)-4(y-4)=0
5(y-1)=3(x+5)
3x-4y=-13
3x-5y=-20
y=-7
x=5
希望你能看懂，祝你学习进步
答
1.x-2y=3,2x-4y=6
x/5-y/2=7/10 ,2x-5y=7,y=-1,x=1
2.3(x-1)-4(y-4)=0,3x-3-4y+4=0,3x-4y=-1
5(y-1)=3(x+5),5y-5=3x+15,5y-3x=20,y=19,x=25