Matlab few very simple questions, for beginner

1)Draw the graph of the function y = tan (x) / x dotted red in the interval (-3.3) with a hundred points

2)Find the roots of polynomials y =-3x^3+4x^2-x+3

3)Solve the system of equations:

x-y+2z=1

x-2y-z=2

3x-y+5z=3

4) Find a graph of the function y= (xe^-x)/1-e^x,,,,,,,,,on intervale(-5.5) with step 00:01

Any help with this would be highly appreciated, thanks in advance.

Regards.