Answer:
[tex]3 \sqrt{7} [/tex]
Step-by-step explanation:
1) Rewrite 63 as its prime factors.
[tex] \sqrt{3 \times 3 \times 7} [/tex]
2) Group the same prime factors into pairs.
[tex] \sqrt{(3 \times 3) \times 7} [/tex]
3) Rewrite each pair in exponent form.
[tex] \sqrt{ {3}^{2} \times 7 } [/tex]
3) Use this rule
[tex] \sqrt{ {x}^{2} } = x[/tex]
[tex]3 \sqrt{7} [/tex]
