Test Fоrmulаs:m=y2-y1x2-x1; y=mx+bJоhnny hаs 1470 fоllowers on Twitter. After а particularly moronic sequence of political tweets, he begins to lose 15 followers a day at a steady rate.Part a) If "f " represents the number of followers and "d " represents the number of days, write a linear equation to model this situation.Part b) How many followers will Johnny have after 25 days?Part c) How many days will it take Johnny to lose all his followers?