Answer
a) $y=-40x+5700$
b) $5420$ cinema sites
Work Step by Step
a) Based on the information given, the following ordered pairs can be made:
$(0,5700)$ and $(4,5540)$
A slope can be found from these two ordered pairs as follows:
$m = \frac{y_2-y_1}{x_2-x_1}=\frac{5540-5700}{4-0} = -40$
The y-intercept is 5700, since when $x=0$, $y=5700$.
Thus the equation is $y=-40x+5700$.
b) 2010 is 7 years past 2003, so $x=7$.
$y=-40(7)+5700=5420$