Aline has a slope of -9 and includes the points (v, 6) and (1, -3). what is the value of v

Y=Mx+c
use the given point!
-3=-9(1)+c
-3=-9+c
c=6
so we found that the equation of the line is:
y=-9x+6
now the the new point
so we're given the y coordinate we need to find the X
so, plug in the y value in to the equation we wrote
6=-9x+6
0=-9x
X=0
that is your v 0