X+y=4,Xy=-12 求(1)XxX+yxy (2)XxXxy+Xxyxy
问题描述:
X+y=4,Xy=-12 求(1)XxX+yxy (2)XxXxy+Xxyxy
答
(1)XxX+yxy
=(x+y)^2-2xy
=4^2+2*12
=16+28
=44
(2)XxXxy+Xxyxy
=xy*(x+y)
=4*(-12)
=-48
不懂可追问,有帮助请采纳,谢谢!