Bài1:
$\sqrt{x+1}+2(x+1)=x-1+\sqrt{1-x}+3\sqrt{1-x^2}$
Bài2:
$\sqrt[3]{x+1}+\sqrt[3]{x^2}=\sqrt[3]{x}+\sqrt[3]{x^2+x}$
Bài 3
$\sqrt{x+2}=\frac{x+2+2\sqrt{2x+1}}{x+\sqrt{2x+1}}$
Bài 4
$x\sqrt{2x+3}+3(\sqrt{x+5}+1)=3x+\sqrt{2x^2+3x+15}+\sqrt{2x+3}$
Bài 5
$4\sqrt{x^2+x+1}=1+5x+4x^2-2x^3-x^4$