x+y+z括号平方括号平方怎么计算

x+y+z括号平方括号平方怎么计算
2025-04-09 10:19:47
推荐回答(2个)
回答1:

(x+y+z)^2=[(x+y)+z]^2
=(x+y)^2+2(x+y)z+z^2
=x^2+y^2+z^2+2xy+2xz+2yz.

回答2:

(x+y+z)²=x²+y²+z²+2xy+2yz+2xz