y2 = b/x； /[y2 is inversely proportional to X]/

Substitute y 1 y2 into y=y 1+y2 to obtain the following formula:

y = a(x- 1)+b/x；

We also know that when x= 1, y = 2；; When x=2, y = 4；; replace

2 = a( 1- 1)+b/ 1； Found that b=2

4 = a(2- 1)+b/2； Substitute b to get a=3.

Therefore, the function: y = 3 (x-1)+2/x.

The second question:

Substitute x =-3 and y = 2 into the proportional function y=kx and 2=k(-3) to get k =-2/3;

Therefore, the first function is y =-2/3x;

Substitute x =-3 and y = 2 into the inverse proportional function y=n/x and 2=n/(-3) to get n =-6;

Therefore, the second function is y =-6/x;