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 :)
To solve this problem, first we have to figure out how many total rolls Hanna buys.
3 packs*36 rolls in each pack = 108 total rolls
2 packs*24 rolls in each pack = 48 total rolls
108 rolls + 48 rolls = 156 rolls.
Next, it says that Hanna uses 8 rolls of film. To model this in our expression, we need to subtract 8 rolls from our total amount.
156-8 = 146 rolls
Hanna has 146 rolls left.
(DVD player+ TV)= 49.36+705.20= 754.56
754.56/12=62.88
She will have to pay $62.88 each time