Đáp án:
`C=5`
Giải thích các bước giải:
`C=\sqrt{5\sqrt{3}+5\sqrt{48-10\sqrt{7+4\sqrt{3}}}}`
`=\sqrt{5\sqrt{3}+5\sqrt{48-10\sqrt{2^2+2.2.\sqrt{3}+3}}}`
`=\sqrt{5\sqrt{3}+5\sqrt{48-10\sqrt{(2+\sqrt{3})^2}}}`
`=\sqrt{5\sqrt{3}+5\sqrt{48-10.(2+\sqrt{3})}}`
`=\sqrt{5\sqrt{3}+5\sqrt{28-10\sqrt{3}}}`
`=\sqrt{5\sqrt{3}+5\sqrt{5^2-2.5.\sqrt{3}+3}}`
`=\sqrt{5\sqrt{3}+5\sqrt{(5-\sqrt{3})^2}}`
`=\sqrt{5\sqrt{3}+5.(5-\sqrt{3})}`
`=\sqrt{5\sqrt{3}+5^2-5\sqrt{3}}=\sqrt{5^2}=5`
Vậy `C=5`
