Question

Answer 1

\(a,ĐK:x\ge0;x\ne\dfrac{9}{4}\\ b,C=\dfrac{\left(2\sqrt{x}-3\right)\left(2\sqrt{x}+3\right)}{2\sqrt{x}-3}=2\sqrt{x}+3\\ c,x=4+2\sqrt{3}=\left(\sqrt{3}+1\right)^2\\ \Leftrightarrow C=2\left(\sqrt{3}+1\right)+3=2\sqrt{3}+5\)