Which set of ordered pairs represents a function? A.{(2,7),(2,8), (3,8)}
B. {(3,2), (3, 3), (3,4)}
C. {(4,1),(5,1),(4,4)}
D {(5,6), (8,6), (9,6)}

Ineed to know the answer to this algebra question.

The width of a rectangle is 20 units. can the perimeter p of the rectangle be 64 units when its length x is 11 units? no, because p = 2x + 2(20) no, because p ≠ 2x + 2(20) yes, because p ≠ 2x + 2(20) yes, because p = 2x + 2(20)

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?