Question

已知x(x-1)-(x的二次方-y)=-2,求2/x的二次方+y的二次方-xy

/是分号

Answer 1

你好！

x(x-1)-(x^2-y)=-2
x^2-x-x^2+y=-2
y-x=-2
x-y=2
(x^2+y^2)/2-xy
=(x^2+y^2-2xy)/2
=(x-y)^2/2
=2^2/2
=2

希望对你有帮助！