2y+3x=46 3y+2x=44怎么解?

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) x-y=2y 0.2x+3y=1 这个二元一次方程怎么解? 【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2= 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 2x=2x+3y+56怎么解 y=－x²-2x+3怎么解 这个方程组{2x+y=6,x+3y+[3x-y]=19怎么解? (3x-5y-11)*(3x-5y-11)+|9x+2y-16|=0怎么解? (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