What expression is equivalent to -9r + 4r

The deck that kenneth is building is in the shape of a parallelogram abcd the measure of angle c is one third the measure of angle b find the measure of each angle of the deck

5x−4≥12 or 12x+5≤−4 can you with this problem

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?