Question 993687
(5,238)
(10,153)
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slope is (153-238)/(10-5)= -85/5 = -17
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y-y1= -17(x-x1).  use either ordered pair.  This is the point slope approach.
y-238= -17(x-5));;point slope formula
y-238= -17x+85
y= -17x+323 slope-intercept form.
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Slope of -17 means that every day, 17 fewer iPhones are being sold.
Intercept of 0 means that on the first day 323 were sold.  Often, y-intercepts are not helpful but may be useful here.

{{{graph(300,200,-3,10,-20,400,-17x+323)}}}