Giúp tui bài này với mn, tui cần gấp dueuhidijei

`a) A = (20 \sqrt{0,03} + 12\sqrt{3} - 1/5 \sqrt{75}) . \sqrt{6}`

`= (20 \sqrt{3}/10 + 12\sqrt{3} - 1/5 \sqrt{5^2 . 3}) . \sqrt{6}`

`= (2\sqrt{3} + 12\sqrt{3} - 1/5 . 5\sqrt{3}) . \sqrt{6}`

`= (2\sqrt{3} + 12\sqrt{3} - \sqrt{3}) . \sqrt{6}`

`= 13\sqrt{3} . \sqrt{6}`

`= 39\sqrt{2}`

`b) B = 1/4 \sqrt{2} - 3/2 \sqrt{4,5} + 2/5 \sqrt{50}`

`= 1/4 \sqrt{2} - 3/2 \sqrt{9/4 .2} + 2/5 \sqrt{5^2 .2}`

`= 1/4 \sqrt{2} - 3/2 . (3\sqrt{2})/2 + 2/5 . 5 \sqrt{2}`

`= 1/4 \sqrt{2} - 9/4 \sqrt{2} + 2\sqrt{2}`

`= 0`

`c) C = 2\sqrt{40 \sqrt{12}} - 2\sqrt{\sqrt{75}} - 3\sqrt{5\sqrt{48}}`

`= 2\sqrt{40 . 2\sqrt{3}} - 2 \sqrt{5\sqrt{3}} - 3\sqrt{5 . 4\sqrt{3}}`

`= 2\sqrt{80 \sqrt{3}} - 2\sqrt{5\sqrt{3}} - 3\sqrt{20\sqrt{3}}`

`= 2 . 4\sqrt{5\sqrt{3}} - 2\sqrt{5\sqrt{3}} - 3 . 2\sqrt{5\sqrt{3}}`

`= 8\sqrt{5\sqrt{3}} - 2 \sqrt{5\sqrt{3}} - 6\sqrt{5\sqrt{3}}`

`= 0`