Sederhanakan 13 per 5+2√3

[tex]= \frac{13}{5 + 2 \sqrt{3} } \times \frac{5 - 2 \sqrt{3} }{5 - 2 \sqrt{3}} \\ \\ = \frac{65 - 26 \sqrt{3} }{25 - 12} \\ \\ = \frac{65 - 26 \sqrt{3}}{13} \\ \\ = 5 - 2 \sqrt{3}. [/tex]