Afriend gives you two baseball cards for your birthday. afterwards you start collecting them. find and interpret the slope and the y-intercept of the line that represents this situation

You have 2 cards upfront, so the constant term in this linear equation is 2.  The slope represents how many more cards you buy or acquire per day, week or month (depending upon how eager you are to fatten your collection).  ;)

y = 2 + (rate of acquisition of cards)(time)

y = 2 + rt