nomor 4 itu gimana ya ngerjainnya?

[tex] \frac{ \sqrt{27} + \sqrt{72} }{ \sqrt{48} + \sqrt{18} } \\ = \frac{3 \sqrt{3} + 6 \sqrt{2} }{4 \sqrt{3} + 3 \sqrt{2} } \\ = \frac{3 \sqrt{3} + 6 \sqrt{2} }{4 \sqrt{3} + 3 \sqrt{2} } \times \frac{4 \sqrt{3} - 3 \sqrt{2}}{4 \sqrt{3} - 3 \sqrt{2}} \\ = \frac{(3 \sqrt{3} + 6 \sqrt{2}) \times (4 \sqrt{3} - 3 \sqrt{2})}{16 \times 3 - 9 \times 2} \\ = \frac{(3 \sqrt{3} + 6 \sqrt{2}) \times (4 \sqrt{3} - 3 \sqrt{2})}{30} \\ = \frac{3( \sqrt{3} + 2 \sqrt{2}) \times( 4 \sqrt{3} - 3 \sqrt{2})}{30} \\ = \frac{( \sqrt{3} + 2 \sqrt{2}) \times( 4 \sqrt{3} - 3 \sqrt{2})}{10} \\ = \frac{ 12 - 3 \sqrt{6} + 8 \sqrt{6} - 12}{10} \\ = \frac{5 \sqrt{6} }{10} \\ = \frac{ \sqrt{6} }{2} \\ = \frac{1}{2} \sqrt{6} [/tex]

Jadi, jawabannya C.