Answer:
[tex]3\sqrt7[/tex]
Step-by-step explanation:
This is because you can split 63 into two numbers, [tex]\sqrt{9}[/tex] and [tex]\sqrt{7}[/tex]. When you simplify [tex]\sqrt{9}[/tex] turns into 3 but [tex]\sqrt{7}[/tex] will not simplify further so it will be [tex]3\sqrt{7}[/tex].
