I need help with algebra

Question

Simplify 

Answer 1

³√(729)

⁼³√9³

cancel out square root and exponent

⁼³√9³

=9

Answer 2

Could try the divisibility rule for 9: If the sum of the digits of any number is divisible by 9, then the number is divisible by 9. 7 + 2 + 9 = 18 which is divisible by 9. 729/9 = 81. Can do same again: 81/9 = 9. So it looks like 9 x 9 x 9 is 729 and 729^1/3 , or the cube root of 729, is 9.

Could also use logarithms.