Let C represents the circumference and d represent diameter since pi is about 3.14 which formula is reasonable? D/3.14 = C

Or

C/D = 3.14

Find an equation of the line perpendicular to the graph of 28x-7y=9 that passes through the point at (4,1)

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?

Which expression is equivalent to -12(3x-3/4)