Simplify. express in simplest form. help!!!?

Question

i really need help in these problems please!!!!!!

1. 3√13/3

2. 3√2 + 5√2

3. 3√2 + √50

4. (√3 - √5)(√3 - √5)

Answer 1

1. the 3's divide out and leaves you with sq. rt of 13

2.  Add the coefficients and get 8 sq.rt 2

3,  3 sqrt 2 + sq.rt 25 (sqrt 2)

       3 sqrt 2 + 5sqrt 2

             8 sqrt 2

4.  Foil

Answer 2

1. √13

2. 8√2

3. 8√2

4. 8-2√15