x
∵x(x-1)-(x2-y)=-2, ∴x2-x-x2+y=-2, ∴x-y=2, ∴ x2+y2 2-xy= x2+y2−2xy 2= (x−y)2 2=2.
已知x(x-1)-(x2-y)=-2,求x
已知x-y+1,X2+Y2=25 求(x+y)2和x2-xy+y2的值
已知(x-x2)+(x2-y)=1,求代数式12(x
已知x(x+1)-(x2-y)=-3,求代数式[(x-2y)2+(x-2y)(x+2y)-2x(2x-y)]÷2x的值.
已知X 、Y为实数,Y=根下{(X2-4)+根下(4-X2)+1}除以x-2,求3X+4Y得值
已知x(x-1)-(x2-y)=-3,求x2+y2-2xy的值.
已知:x2+4x+y2-6y+13=0,求(x-2y)/(x²+y²)
已知实数x.y满足(x2+y2)(x2+y2-1)=2,求x2+y2的值
已知x2+y2=20,x2+xy-2y2=2(x+2y),求x+y的值
已知函数y=x+2x2+x+1(x>-2)
已知x+y=4,xy=3求(1)x2=y2 (2)x-y的值
已知x(x-1)-(x2-y)=-3,求x2+y2-2xy的值
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