A wireless company offers two cell phone plans. For the month of September Plan A charges $35 plus $0.25 per minute for calls. Plan B charges $20 plus $0.50 per minute for calls. For what number of minutes do both plans cost the same amount? i really need help

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? )