#### Answer

a) $(0, 302)$ and $(4,322)$
b) $y=5x+302$
c) 312 million subscriptions

#### Work Step by Step

a)
$2003-2003 = 0$
$2007-2003 = 4$
2003 had 302 million subscriptions
2007 had 322 million subscriptions
b)
$m= (322-302)/(4-0)$
$m = 20/4$
$m=5$
$y=mx+b$
$y=5x+b$
$302 = 5*0+ b$
$302 = 0+b$
$302 = b$
$y=5x+302$
c)
$y=5x+302$
$2005-2003 = 2$
$y=5x+302$
$y=5*2+302$
$y=10+302$
$y=312$