Đáp án:
`B=10-14\sqrt{2}`
`C=25\sqrt{3}-8`
`D=-8\sqrt{5}-3`
Giải thích các bước giải:
`B=3\sqrt{(3-\sqrt{2})^2}-4\sqrt{32}+2\sqrt{18}-\sqrt{(\sqrt{2}-1)^2}`
`B=3|3-\sqrt{2}|-4\sqrt{2.4^2}+2\sqrt{2.3^2}-|\sqrt{2}-1|`
`B=3.(3-\sqrt{2})-4.4\sqrt{2}+2.3.\sqrt{2}-(\sqrt{2}-1)`
`B=9-3\sqrt{2}-16\sqrt{2}+6\sqrt{2}-\sqrt{2}+1`
`B=10-14\sqrt{2}`
$\\$
`C=3\sqrt{48}+\sqrt{108}-2\sqrt{(4-2\sqrt{3})^2}+\sqrt{27}`
`C=3\sqrt{3.4^2}+\sqrt{3.6^2}-2|4-2\sqrt{3}|+\sqrt{3.3^2}`
`C=3.4\sqrt{3}+6\sqrt{3}-2.(4-2\sqrt{3})+3\sqrt{3}`
`C=12\sqrt{3}+6\sqrt{3}-8+4\sqrt{3}+3\sqrt{3}`
`C=25\sqrt{3}-8`
$\\$
`D=2\sqrt{(2-\sqrt{3})^2}-\sqrt{(7-2\sqrt{3})^2}+\sqrt{20}-2\sqrt{125}`
`D=2|2-\sqrt{3}|-|7-2\sqrt{3}|+\sqrt{5.2^2}-2\sqrt{5.5^2}`
`=2.(2-\sqrt{3})-(7-2\sqrt{3})+2\sqrt{5}-2.5\sqrt{5}`
`D=4-2\sqrt{3}-7+2\sqrt{3}+2\sqrt{5}-10\sqrt{5}`
`D=-8\sqrt{5}-3`