There's a couple of problems that i don't understand how to do. So please explain to me step-by-step how you solved each one. thank you!

1. True velocity of a jet: A jet is flying through a wind that's blowing w/ a speed of 55mi/h in the direction N 30 degress. The jet has a speed of 765mi/h relative to the air,and the pilot heads the jet in the direction N 45 degrees east.
a. Express the velocity of the wind as a vector in component form
b. express velocity of the jet relative to the air as a vector in component form.
c. find the true velocity of the jet as a vector.
d. find the true speed and direction of the jet.

2. Suppose that n vectors can be placed head to tail in the plane so that they form a polygon(hexagon). explain why the sum of these vectors is 0.