You seem to be sharing two points: (4,7)(-12,3).
But you don't explain what you're looking for.
I must assume you want to find the equation of the str. line thru these 2 pts, in std. form. Ax+By+C=0.
1. Find the slope of the line thrugh (4,7)(-12,3): rise is -4 and run is -16.
Thus the slope is -4/16, or -1/4.
2. Write out the slope-intercept equation of this line: subst. m = -1/4 and the coordinates of either given point:
y = mx + b becomes y = (-1/4)x + b
Let's subst. 4 for x and 7 for y: 7 = (-1/4)(4) + b, or
7 = -1 + b. Then b = 8.
Convert this to the equation in std. form:
y = (-1/4)x + 8 Mult all three terms by 4 to eliminate fractions.
4y = -x + 32, or 0 = -4y -x + 32, or 4y + x - 32 = 0 (answer)