Question 476488
It's not the solution because {{{root(6,15)}}} and {{{root(4,8)}}} are not like terms, so you can't combine them. They are only like terms if the indices (the small numbers up top) and the radicands are equal. However, the first index (6) is NOT equal to the second index (4), so the two radical expressions are NOT like terms. In addition, the radicands are not equal as well.