For the first one, is the square root just over the 9 or is it over the 4/3 too?
For the second one, you can just treat this like any squaring of a binomial. You would use FOIL. So you should have (4 - 3√2)*(4 - 3√2) and then you just distribute through to find the answer. Use First (4*4), Outside (4*-3√2), Inside (-3√2 * 4) and last (-3√2*-3√2). You then add these together for the final answer.
For the last one, it isn't clear what your powers are, can you rewrite them please?