1.{3x+2y=73x-4y+12 {x-6y=-23x+4y=53 {8x+3y+2=06x+5y+7=04 {2x

来源：学生作业帮编辑：作业帮分类：数学作业时间：2024/04/28 02:26:07

1.{3x+2y=7
3x-4y+1
2 {x-6y=-2
3x+4y=5
3 {8x+3y+2=0
6x+5y+7=0
4 {2x-y=6
50%x+12.5%y=25%×3
5 {|x |+y=2
|x |+2y=3
希望可以有过程,用加减消元法谢谢了

1.3x+2y=7
3x-4y=1
两式直接相减,得6y=6,y=1,代入一式解得x=5/3
2.x-6y=-2
3x+4y=5
一式乘以3,3x-18y=-6
3x+4y=5
两式相减22y=11,y=1/2,x=1
3 {8x+3y+2=0
6x+5y+7=0
一式乘以3,二式乘以4
24x+9y+6=0
24x+20y+28=0
得11y=-22,y=-2,x=1/2
4 {2x-y=6
50%x+12.5%y=25%×3
将二式化简为1/2x+1/8y=3/4乘以4,2x+1/2y=3
2x-y=6
得3/2y=-3 ,y=-2,x=2
5 {|x |+y=2
|x |+2y=3
相减得y=1,|x |=1,所以x=1或-1

{3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1 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 【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2= 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) (4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuai 6(x-y)-2(x+y)=14 3(x-y)+(x+y)=5 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