Question

a) tính b) tìm x

Answer 1

a, \(\sqrt{\left(3-\sqrt{11}\right)^2}+\sqrt{11}\)

\(=\sqrt{11}-3+\sqrt{11}\)

\(=2\sqrt{11}-3\)

Answer 2

b, ĐK: \(x\ge-5\)

\(\dfrac{2}{3}\sqrt{9x+45}-9=6-3\sqrt{x+5}\)

\(\Leftrightarrow\dfrac{2}{3}.3\sqrt{x+5}-9=6-3\sqrt{x+5}\)

\(\Leftrightarrow2\sqrt{x+5}-9=6-3\sqrt{x+5}\)

\(\Leftrightarrow5\sqrt{x+5}=15\)

\(\Leftrightarrow\sqrt{x+5}=3\)

\(\Leftrightarrow x+5=9\)

\(\Leftrightarrow x=4\left(tm\right)\)