Let's do it !
You should show that the equation of a line is like : [tex]y = mx + p[/tex].
By the way, you must know that two parallel lines have the same slop, so here the slope will be : [tex]m = 2[/tex].
So now, we have the slope and the equation is [tex]y = 2x + p[/tex]. We just have to find the letter "p" which correspond to the intercept.
Here we have :
x = 1
y = -1.
Therefore :
y = 2x + p
-1 = 2*1 + p
-1 = 2 + p
-1 -2 = p
-3 = p.
In short, the answer would be : y = 2x - 3.
Hope this helps !
Photon