Mike and kim invest $18,000 in equipment to print yearbooks for school. each yearbook costs $5 to print and sells for $15. how many yearbooks must they sell before their business breaks even?
a. 1,100 yearbooks
b. 1,200 yearsbooks
c. 3,600 yearbooks
d. 1,800 yearsbooks

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? )