\(b^5\sqrt{\frac{a^2+6a+9}{b^8}}\)
= \(b^5\sqrt{\frac{\left(a+3\right)^2}{b^8}}\)
= \(b^5\frac{\left|a+3\right|}{b^4}\)
= \(b\left|a+3\right|\)
Nếu a < -3 thì \(b\left|a+3\right|=b\left(-a-3\right)=-ab-3b\)
Nếu \(a\ge-3\) thì \(b\left|a+3\right|=b\left(a+3\right)=ab+3b\)
Chúc bạn làm bài tốt :)