one way is to factor and group and get every 3 729=3 times 3 times 3 times 3 times 3 times 3 so we group the ones that happen 3 times 729=(3*3*3) times (3*3*3) we know that we can take the cube root of each group and multiply the result 729=[tex]( \sqrt[3]{3*3*3})( \sqrt[3]{3*3*3})[/tex]=(3)(3)=9
