（1)x=10y,3x-2y=12 (2)x=7,2x-3y=-4 (3)2x+y=32,2x=y 今天我要用

来源：学生作业帮编辑：大师作文网作业帮分类：数学作业时间：2024/11/15 23:12:05

（1)
x=10y代入3x-2y=12
3*10y-2y=12
28y=12
y=3/7
x=30/7
(2)x=7代入2x-3y=-4
14-3y=-4
3y=14+4
y=8
x=7
(3)2x+y=32,2x=y
y=2x代入
2x+2x=32
4x=32
x=8
y=2x=16

{3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1 已知X-Y/X+Y=3,求代数式2(x-y)/X+Y-3X+Y/X+Y 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) 先化简再求值(x-y)(x+y)-(x-2y) 的完全平方+x(3x-5y)-(x-y)(x-2y),其中x=1/2 y (3x-y)^2+(3x+y)(3x-y),x=1,y=-2 x+y/2+x-y/3=6,4(x+y)-3(x-y)=-20 {(x+y)/2+(x-y)/3=6 4(x+y)-3(x-y)=-20 4(x+y)-3(x-y)=-20,2/x+y+3/x-y=6 3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27 若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于 (x+y)(x+2y)(x+3y)(x+4y)=-40 化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1