Answer: -2
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Draw a vertical line through 4 on the x axis. This vertical line crosses the parabola at some point (which we'll call point A). Draw a horizontal line from point A to the y axis and note how it lands on y = 12. Therefore the point (4,12) is on this parabola.
Repeat the same steps as before to find that (8,4) is also on the parabola
We need to find the slope of the line through (4,12) and (8,4)
m = (y2 - y1)/(x2 - x1)
m = (4-12)/(8 - 4)
m = -8/4
m = -2
The slope of this line is -2 meaning that the average rate of change from x = 4 to x = 8 is -2.
The line goes down 2 units each time you move to the right 1 unit.
Let's assume that a,b&c are in one straight line, so cannot form a triangle with each other. Now, total possible Triangle that can be formed choosing any 3 points without any colinear constraint is 8C3 = 56
solve for "a", once you get "a", plug it back into either equation to get "b"
The a value affects the graph by vertically stretching or compressing the graph.
The r and s values affect the zeros, or x intercepts of the parabola, and therefore the vertex.
Hope this helps!
