Have a feq homework problems that i cant seem to solve

Multiply

1.(5 sq root over 2) (-4 sq root over 8)

2.(4 sq rt 2+ sq rt 3) (4 sq rt 2- sq rt 3)

Simplify

3.sq rt -12 x sq rt -9

4.(3-i) (6+3i)

5.(3-2i)/(4-sq rt-9)

6. (3+i) (4-2i)

Thanks for any help