Acomedy show sells lower level tickets for 75$. on the opening night 2135 tickets were sold for a total 145145. what system of equations describe the situation above

Agroup 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?