Question

7-4radical3,totul sub radical

Answer 1

$\sqrt{7-4\sqrt3}=\sqrt{4-2\cdot 2\cdot\sqrt3+3}=\sqrt{2^2-2\cdot 2\cdot\sqrt3+(\sqrt3)^2}=\\=\sqrt{(2-\sqrt3)^2}=|2-\sqrt3|=2-\sqrt3.$

Green eyes.