how do i answer this please?

Answer:
a) [tex]5\sqrt{3} + 3\sqrt{5}[/tex]
b) [tex]4(\sqrt{2} + \sqrt{7})[/tex]
Step-by-step explanation:
a) [tex]9\sqrt{3} - 4\sqrt{3} +\sqrt{5} + 2\sqrt{5}[/tex]
Taking √3 & √5 common respectively,
[tex]=> \sqrt{3} (9 - 4) + \sqrt{5} (1 + 2)[/tex]
[tex]=> 5\sqrt{3} + 3\sqrt{5}[/tex]
b) [tex]10\sqrt{2} + 4\sqrt{7} - 6\sqrt{2}[/tex]
Taking √2 common ,
[tex]=> \sqrt{2} (10-6) + 4\sqrt{7}[/tex]
[tex]=> 4\sqrt{2} + 4\sqrt{7}[/tex]
Taking 4 common ,
[tex]=> 4(\sqrt{2} + \sqrt{7})[/tex]