若|3x-y-1|和2x+y−4
(x+y)和(x-y)各看成一个整体,合并同类项2(x+y)-3(x-y)²+3(x+y)+4(x-y)
若|3x-y-1|和2x+y−4
解方程组3(x+y)-4(x-y)=4和(x+y)/2+(x-y)/6=1
已知X和Y满足3X+4Y=2,X-Y-1/7
若x=-1/4,能否确定代数式(2x-y)(2x+y)+(2x-y)(y-4x)+2y(y-3x)的值?
(x+2)(x+3) (x-4)(x+1) (y+4)(y-2) (y-5)(y-3)
已知X,Y,满足(X+3Y)(X-3Y)=-10(Y^2-6/5)和2X(Y-1)+4(1/2X-1)=0
{3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1
计算:1/(x-y)-1/(x+y)-2y/(x^2+y^2)-4y^3/(x^4+y^4)-8x^7/(x^8+y^8
化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1
{x-y+xy=1,3x-y=4}和{x/2+y/2=2y,y=2x/3}哪个是二元一次方程组?
若2x-3y+4=0则x(x*x-1)+x(5-x*x)-6y+7