A unit cube is removed from a cube of side x cm. If the volume of the remaining cube is 728 cm^3, then find the side of the cube?

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Answer 1 · 2018-05-10T08:36:42

The cube has sides #9cm# long.

The simplest way to solve this is:

After you remove #1cm^3# you have a volume of #728cm^3#,so before removal you must have had #729cm^3#

Volume of a cube with sides #x# is:

#x^3#

This is equal to #729cm^3#

#:.#

#x^3=729#

#x=root(3)(729)=9#

The cube has sides #9cm# long.