Solve the second equation for y:

x + y = 2
    y = 2 - x

Substitute (2 - x) for y in the first equation:






,  
,   

Substitute x = -2 in

  y = 2 - x
  y = 2 - (-2)
  y = 2 + 2
  y = 4

So one point where they cross is (-2,4).

Substitute x = 1 in

  y = 2 - x
  y = 2 - (1)
  y = 2 - 1
  y = 1

So another point where they cross is (1,1).

Get some points on     x + y = 2, (-1,3), (-2,4), (0,2), (1,1), (2,0)
Get some points on     x^2 - y = 0, (-2,4), (-1,1), (0,0), (1,1), (2,4) 



Edwin