x.y都是自然数,且x(x-u)-y(y-x)+12,求x.y得值
问题描述：
x.y都是自然数,且x(x-u)-y(y-x)+12,求x.y得值
快
1
且x(x-y)-y(y-x)=12
答
x(x-y)-y(y-x)=12
x(x-y)+y(x-y)=12
(x-y)(x+y)=12
x^-y^=12
x=4;y=2