求X的值和Y的值:(X*75.5)+(Y*81)/X+Y=78
已知x+y=-5,x*x+y*y=19求xy和(x-y)*(x-y)的值
已知x-y/x=x/x-2y(y不等于0),求x:y的值
已知x,y为自然数,x>y且满足(x+y)+(x+xy-y)+x/y=243求x+y的值
若|x+y-1|+(x-y-2)²=0,求代数式(x+2y)(x-2y)-(2x-y)(-y-2x)的值.
已知x+y=-5,x*x*x+y*y=19,求xy和(x-y)的值
(X+y)(x+y-1)-12=0求x+y的值
正数x,y满足x^2-y^2=2xy,求(x-y)/(x+y)的值
(x+y)(x+y+10)+25=0 x-y=3.求x,y的值
已知x=3分之1,y=二分之一,求代数式x-(x+y)+(x+2y)-(x+3y)+...-(x+13y)的值
已知x+y=10,xy=4,求x²+y²和(x-y)²的值
已知:(3x-y-4)2+|4x+y-3|=0,求x和y的值.
X²+Y²=9.(X+Y)²=13 求XY和X+Y的值