Aline has a slope of -1 and includes the points 0,-1 t,-8 what is the value of t

So we will begin with the equation for any slope
it is
(y2 - y1)/(x2 - x1)
and we will put each given point in its place
(-8-(-1)) / (t -(0))
then sum up the nominator
-1 = (-7) / t -0
and to find t we have to divide -7 over -1 and add -0 which will give us 7
So the value of t is 7