Question

2)Đưa thừa số vào trong dấu căn 

a)\(2\sqrt{24}\)

b)\(-3\sqrt{15}\)

c)\(a\sqrt{\dfrac{3}{a}}\)

d)a\(\sqrt{2}\)

Answer 1

\(a,2\sqrt{24}=\sqrt{4}.\sqrt{24}=\sqrt{96}\\ b,-3\sqrt{15}=-\sqrt{9}.\sqrt{15}=-\sqrt{135}\\ c,a\sqrt{\dfrac{3}{a}}=\sqrt{a^2}.\sqrt{\dfrac{3}{a}}=\sqrt{3a}\)

Nếu \(a\ge0\Rightarrow a=\sqrt{a^2}\)

\(a\sqrt{2}=\sqrt{a^2}.\sqrt{2}=\sqrt{2a^2}\)

Nếu \(a< 0\Rightarrow a=-\sqrt{a^2}\)

\(a\sqrt{2}=-\sqrt{a^2}.\sqrt{2}=-\sqrt{2a^2}\)

Answer 2

a, \(\sqrt{2^2.24}=\sqrt{96}\)

b,\(-\sqrt{3^2.15}=-\sqrt{135}\)

c,\(\sqrt{a^2.\dfrac{3}{a}}=\sqrt{\dfrac{3a^2}{a}}=\sqrt{3a}\)

d,\(\sqrt{a^2.2}=\sqrt{2a^2}\)