A line perpendicular means that the slope is the negative reciprocal of the slope given. Since m=3 in the given equation, the slope in the perpendicular line has to be m = -1/3. The y-intercept can be any number.
So a line perpendicular would be y = -1/3x + b
Since you can plug anything into b, you can get many different answers. For example, y = -1/3x + 7 or y = -1/3x - 2
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 :)
Answer:
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Step-by-step explanation:
