Answer: Choice D) f(x) = 24x - 111
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Explanation:
The two points on this line are (4,-15) and (7,57)
Compute the slope to get m = 24 (see attached image figure 1). I used the slope formula. The idea is to subtract the y values together, do the same for the x values in the same order as the y values, and divide the results.
Once you know m = 24, use it and a point on the line to find the y intercept b (see figure 2). You should find that b = -111
That is why the answer is y = 24x - 111 or f(x) = 24x - 111.
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As a check, we should be able to plug in x = 4 to get y = -15
y = 24x-111
y = 24*4-111
y = 96-111
y = -15
we get the proper y value we want. The same should be said for x = 7 leading to y = 57
y = 24x-111
y = 24*7-111
y = 168-111
y = 57
we get the proper output here as well. The answer is confirmed.
