If l=25, n=8, d=3, and l=a+(n-1)d, find the value of a (I got a=2 am I right if not whats the answer?)

Really need on these. i have no idea what to do

Graph the line that represents a proportional relationship between d and t with the property that an increase of 33 units in t corresponds to an increase of 44 units in d. what is the unit rate of change of dd with respect to t? (that is, a change of 11 unit in t will correspond to a change of how many units in d? )

What’s the range cuz i can’t find it?