The percentage of homes with digital tv services stood at 5% at the beginning of 1999 (t-0) and was projected to grow linearly so that, at the beginning of 2003 (t=4), the percentage of such homes was 25 %

1. Derive an equation of the line passing through the points A(0,5) and B(4,25)
2. Using the equation found in part a find the percentage of homes with digital services at the beginning of 2001