y = x means that the line is going 1 value of x for every 1 value of y.
The intersection would be at the (0,0).
However, y = x+2 would have a intersection at (0,2) when y-axis have the value 2. The slope doesn't increase, because the derivative of both slopes gives us y = 1.
Therefore, the line shifts up 2 units.
Hope you understood!
Good luck ;)
Sincerely
Astrophysicist. D
