If line k in the xy-plane has equation y = mx + b, where
m and b are constants, what is the slope of k ?

(1) k is parallel to the line with equation y = (1 - m)x + b + 1.

(2) k intersects the line with equation y = 2x + 3 at the point (2,7).

I can understand that St (1) is sufficient but i cannot understand why st(2) is not sufficient.