As shown in figure
[tex]5[/tex]

Answer:
12. [tex]\sqrt{3}(2+\sqrt{6} )[/tex]
13. 9√2
Step-by-step explanation:
12. 4√3-√12+√18
4√3-2√3+√18
2√3+√18
[tex]\sqrt{3}(2+\sqrt{6} )[/tex]
13.(2√12-3√1/3)√6
(4√3 - 3√(1/3))√6
4√18 - 3√(6/3)
12√2-3√2
9√2