(1) 3x+2y=12 (2) 2(x+1)=3(x-1)+3 方程怎么解?要过程,谢谢(1) 3x+2y=12 (2) 2(x+1)=3(x-1)+3 方程怎么解?要过程,谢谢!

若2/x-1/y=3,求[y/x-y/x-y(x-y/x-x+y)]/x-2y/x的值 (3x-y)^2+(3x+y)(3x-y),x=1,y=-2 二元一次方程 ：2(x+y)-(x-y)=3 (x+y)-2(x-y)=1 (x-y)/(x+y)=3求( 3x-2y-1)/(x+y-5) 2(x+y)-3(x-y)=1 6(x+y)+(x-y)=51 {3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1 变量x,y满足约束条件,x+y>=3,x-y>=-1,2x-y (x-y)^2+(x+y)(x-y) 其中 X =3 Y=-1 先化简再求值; 解方程组 x(x-y)-y(x+y)+2xy 其中x=2 ,y=-22.x[x-x(x-1)],其中x=-2解方程组4x+3y=12x-y=32.y+1=2x 4x-y=2 3.2x+2y=0 2x-y+24=0 函数,y=3x/(x^2+x+1) ,x 函数y=3x/(x^2+x+1) （x x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 x+y+2(-x-y+1)=3(1-y-x)-4-(y+x-1),x+y=? {(x+y)/2+(x-y)/3=1,(x+y)-5(x-y)=2.求x=?,y=? 解方程组:(x+3)(y-2)=(x-3)(y+10),(x+1)(y+3)=(x-2)(y+12) 解方程：（x+3)(y-2)=(x-3)(y+10) (x-1)(y+3)=(x+2)(y+12) 解方程组{2(x-y)/3 - x+y/4=-1 6(x+y)-41(x-y)=12 12y(x-y)^2-8(x-y)^3=?