4x+3y=5,X—2y=4,求x=()y=()
已知x=1/3,y=-1/2,求代数式x-(x+y)+(x+2y)-(x+3y)+(x+4y)-(x+5y)+...-(
已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)
已知(x+2)^2+|x+y+5|=0,求3x^2y-[2x^2y-(2xy-x^2y)-4x^2]-xy
若|x+2y-1|+y²+4y+4=0,求(2x-y)²-2(2x-y)(x+2y)+(x+2y)&
3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27
若实数x、y满足x平方+y平方-4x-2y+5=0,求根号8y-2x分之(根号x)+y
已知x=y+3,求代数式4分之一(x-y)的平方-0.3(x-y)+0.75(x-y)的平方+10分之3(x-y)-2(
已知:4x = 5y,求(x+y) :y
已知3x-2y-5z=0,2x-5y+4z=0,且x,y,z都不为0,求(3x*x+y*y+4z*z)/(5x*x+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x²+y²+5=2x+4y,求【2x²-(x-y)(x-y)】【(x+y-1)(x-y
已知2x+y=4,求代数式[(x+y)2-(x-y)2-2y(x-12