①｛ x/2=y/3； 30% ·x -16% ·y=2%② 2x+3y/4+2x-3y/3 =7 ; 2x+3y/3+2x-3y/2=8

①｛ x/2=y/3； 30% ·x -16% ·y=2%② 2x+3y/4+2x-3y/3 =7 ; 2x+3y/3+2x-3y/2=8 3^x+2x=y,x (x-y) (x-2y)+(x+2y) (x-3y)-2(x-3y) (x-4y)= (x+y)(x-y)+(x-y)平方-(x-y)(3x-y) 其中x=-2 y=3分之一 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) (x+y)(2x-3y)=? x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 |x|=2,|y|=3,且x·y (x-y)^2·(y-x)^3=多少? x-y)^2·(y-x)^3=多少? 2Y：30%=3X：50%求X:Y 若2/x-1/y=3,求[y/x-y/x-y(x-y/x-x+y)]/x-2y/x的值 2(x+y)-3(X-y)=3①4(X+y)+3(x-y)=15② 【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2= {3x+4y=39-2y 5x+3y=2x+30 {3x+4y=39-2y 5x+3y=2x+30 已知x-y=3,求[（x+y)(x-y)-(x-y)^2+2y(x-y)]除以的值 3（x+y)+2(x-3y)=20,30%x+60%y=10%*60