Given that,
63√2−2√3=a√2−b√3
⇒63√2−2√3×3√2+2√33√2+2√3=a√2−b√3
⇒6(3√2−2√3)(3√2)2−(2√3)2=a√2−b√3
⇒6(3√2−2√3)18−12=a√2−b√3
⇒3√2−2√3=a√2−b√3
On comparing that and we get,
⇒a=3andb=2