Shortcut formule on number system

Important shortcut formula on number system :

1.  To find the larger between ³√3 and ⁴√5

Solution: 
 Take lcm of surds which are 3 and 4 here .
Lcm of 3 and 4 is 12 
Convert each surd into surd of 12.
³√3=¹²√3⁴=¹²√81
⁴√5=¹²√5³=¹²√125

Clearly ¹²√125 >¹²√81 
So ⁴√5 is greater.