I'll just do the second one, the only one with a
fraction solution:

{ x + 3y = 11  
{4x - 3y = -2

To eliminate the x's multiply the first equation through
by -4, so that its first term will become -4x and will 
cancel with the 4x in the second equation:

-4x - 12y = -44
 4x -  3y =  -2

Now when we add them term by term vertically we get:

-4x - 12y = -44
 4x -  3y =  -2
---------------
     -15y = -46
        y = 
        y = 

Now to eliminate the y's, we don't need to
multiply either one through because the terms
in y are already opposite and will cancel just
as they are.  So we add term by term vertically:

{ x + 3y = 11  
{4x - 3y = -2
-------------
 5x      =  9
       x = 


Solution is (x,y) = 

Here are the solutions to the others.  You can solve them similar
to the way I solved the second one:


{-x+3y=-1
{x-2y=2 BY elmination:  Solution is (x,y) = (4,1)

{x+y=7
{x+3y=11 by elmination:  Solved above.

{4x-3y=-2
{4x+5y=14 by elmination:  Solution is (x,y) = (1,2)
 

{x+2y=10
{3x-y=9 By elmination  Solution is (x,y) = (4,3)

Edwin