Stanley is filling a water tank that already has 10 gallons of water in it he is filling the tank at the rate of 4.75 gallons per minute. this situation is represented by the following function, where n is the number of minutes

f(n)=10+4.7n

He ! a group of farmers planned to clean 80 acres of wheat per day to finish the work on schedule. right before the work started, they received a new piece of machinery that them clean 10 more acres per day than originally planned. as a result of increased productivity in the last day before the deadline they only had to clean 30 acres. how many acres of wheat did the group of farmers have to clean?