(X^2+Y^2)-15(x^2+y^2)-100=0,求 x^2+y^2
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)
已知x*x-4xy+4y*y=0 求[2x(x+y)-y(x+y)]/(4x*x-4xy+y*y)的值?
y=2x*arctan(y/x),求y‘’
若(x*x+y*y)(x*x+y*y)-4x*x*y*y=0,求代数式(x*x+5xy+y*y)/(x*x+2xy+y*
已知4x=9y求(1)x+y/y (2)y-x/2x
若|x+2y-1|+y²+4y+4=0,求(2x-y)²-2(2x-y)(x+2y)+(x+2y)&
1、x(x-y)(x+y)-x(x+y)^2
已知x-3y=0,求(2x+y)/(x^2-2xy+y^2)X(x-y)
2x-y=2,求[(x²+y²)-(x-y)²+2y(x-y)]÷4y
y=ln(x^2+e^x) 求Y'X
已知2x-y=10,求[(x²+y²)-(x-y)²+2y(x-y)]/4y