已知a,b满足a+b=3,ab=2,则a²+b²=

问题描述:

已知a,b满足a+b=3,ab=2,则a²+b²=
还有题:化简:3a²/ab=

a²+b²
=(a+b)²-2ab
=3²-2×2
=9-4
=5


3a²÷ab=3a/b