已知:①3x-4y=10;②3y+2x=-1;③5x=4-6y;④4x+7=2y-1.解为x=2;y=-1的方程是
已知x=1/3,y=-1/2,求代数式x-(x+y)+(x+2y)-(x+3y)+(x+4y)-(x+5y)+...-(
{3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1
已知:①3x-4y=10;②3y+2x=-1;③5x=4-6y;④4x+7=2y-1.解为x=2;y=-1的方程是
已知X,Y,满足(X+3Y)(X-3Y)=-10(Y^2-6/5)和2X(Y-1)+4(1/2X-1)=0
已知4x=9y求(1)x+y/y (2)y-x/2x
化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1
已知3x-4y/2x+y=1/2 求x/y的值
已知X和Y满足3X+4Y=2,X-Y-1/7
1.已知:x-2y=3,求[(3x+2y)(3x-2y)-(x+2y)(5x-2y)]除4x 的值
已知x²+y²+5=2x+4y,求【2x²-(x-y)(x-y)】【(x+y-1)(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
已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)