Finding the Equation
We can now use the point-slope form (y - y₁) = m(x - x₁)) to write the equation for this line:
⇒ y - (-8) = -1 (x - 8)
y + 8 = - (x - 8)
we could also transform this into the slope-intercept form ( y = mx + c)
since y + 8 = - (x - 8)
⇒ y = - x
To test my answer, I have included a Desmos Graph that I graphed using the information provided in the question and my answer.