\(\sqrt{x+3}+\sqrt{2x-1}=3\left(đk:x\ge\dfrac{1}{2}\right)\)
\(x+3+2x-1+2\sqrt{\left(x+3\right)\left(2x-1\right)}=9\)
\(2\sqrt{\left(x+3\right)\left(2x-1\right)}=7-3x\left(x\le\dfrac{7}{3}\right)\)
\(4\left(2x^2-x+6x-3\right)=49-42x+9x^2\)
\(-x^2+62x-61=0\)
đến đây dùng delta tìm x nha