[질문] (a+b+c)³이거좀풀어주세여

(a+b+c)³=a³+b³+c³+3a²c+3b²c+3a²b+3c²b+3ab²+3ac²+6abc==(a+b)³+c{c(c+3a+3b)+3(a+b)²}=(a+b)³+c²(c+3a+3b)+3c(a+b)²=(a+b+3c)(a+b)²+c²(c+3a+3b)