Hey There,
The equation would be y = 4x - 45
Point slope formula
(y-y1)=m(x-x1)
Plug in the numbers
(y-3)=4(x-12)
Solve for y.
4 * x = 4x
4 * -12 = -48
Bring 3 to the other side (change the sign)
-48 +3 = 45
Therefore, the equation would be y = 4x - 45