Please answer this please

Hi, can anyone show me how to do this problem? 100 points for this. in advance

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?

Atotal of 766 tickets were sold for the school play. they were either adult tickets or student tickets. there were 66 more student tickets sold than adult tickets. how many adult tickets were sold?