若a+2b+3c=12,且a^2+b^2+c^2=ab+bc+ac,则a+b^2+c^3=_____

急求!~~~~~~~~~~谢谢!~~~~~~~~
2024-12-28 04:05:43
推荐回答(2个)
回答1:

解:a^2+b^2+c^2-ab-bc-ca=0
2a^2+2b^2+2c^2-a2b-2bc-2ca=0
(a-b)^2+(b-c)^2+(a-c)^2=0
故有:a-b=0, b-c=0, a-c=0
即:a=b=c
又a+2b+3c=12
因此a=b=c=2
故:a+b^2+c^3=14

回答2:

a^2+b^2+c^2-ab-bc-ca=0
2a^2+2b^2+2c^2-a2b-2bc-2ca=0
(a-b)^2+(b-c)^2+(a-c)^2=0
a+2b+3c=12
a=b=c=2
a+b^2+c^3=14