Bantu isiiinnn dongg

x + y = 5
x + 3y = 2
---------------- (-)
     - 2y = 3
         y = -3/2

subtitusikan y = -3/2 ke 
x + y = 5
x - 3/2 = 5
x = 10/2 + 3/2
x = 13/2