This week I worked with this problem.

I multiplied the conjugate:

When you multiply two exact same square radicals, for instance root 12 here, it just becomes 12. My mistake was keeping the radical.

This led me to a mistake, because I thought there was an exponent to be solved.

I got the incorrect answer of:

The right way was:

This leaves

Which leaves me with:

and to simplify further, I got the final answer of: