Question 36280
y=x+1       --------equation 1
y=-2x-4     --------equation 2

Subtract eq 1 and eq 2
Y term gets cancelled and you get 

(y-y) = x -(-2x) + 1-(-4)
0 = x+2x +1+4
3x + 5 = 0 
3x = -5
x = -5/3

Substitute the value of x = -5/3 in eq 1.
y = x + 1
y = (-5/3) + 1
y = -2/3