3a(b²+9)²-108ab²=3a[(b²+9)²-36b²]=3a[(b²+9)+6b][(b²+9)-6b]=3a(b²+6b+9)(b²-6b-9)=3a(b+3)²(b-3)²很高兴为您解答,【the 1990】团队为您答题.请点击...