a) \(2\sqrt{75}+5\sqrt{27}-4\sqrt{48}\)
\(=2\sqrt{3.25}+5\sqrt{3.9}-4\sqrt{3.16}\)
\(=10\sqrt{3}+15\sqrt{3}-16\sqrt{3}=9\sqrt{3}\)
b) \(\sqrt{4x-12}+\dfrac{1}{3}\sqrt{9x-27}=4+\sqrt{x-3}\left(Đk:x\ge3\right)\)
\(\sqrt{4\left(x-3\right)}+\dfrac{1}{3}\sqrt{9\left(x-3\right)}-\sqrt{x-3}=4\)
\(2\sqrt{x-3}+\sqrt{x-3}-\sqrt{x-3}=4\)
\(\sqrt{x-3}=2\)
\(x-3=4\)
\(x=7\)
Đúng 0
Bình luận (0)
