xy的平方加xy等于多少?
问题描述:
xy的平方加xy等于多少?
答
x^2+2xy+y^2
=(x^2+xy)+(xy+y^2)
=2+7
=9
xy的平方加xy等于多少?
x^2+2xy+y^2
=(x^2+xy)+(xy+y^2)
=2+7
=9