The slope can sometimes be called the gradient, and the equation for the gradient is (y2 - y1)/(x2 - x1). So therefore, you'd do: (-8 - 7)/(4 - -5) which is (-15)/9) which is -1 2/3 or -1.6 (recurring), which is your answer. I hope this helps! Let me know if I've confused you :)
The line plot smallest number always goes first biggest number goes last
Consecutive interior theorem
X+96+96+x= 180
2x+192=180
2x= -12
X=-6