Find how many quarts of 6% butterfat milk and 1% butterfat milk should be mixed to yield 125 quarts of 2% butterfat milk. how many of 6% and how many of 1%?

Me because some of question i don’t understand

Aquadratic equation in standard from is written ax^2= bx+c, where a,b and c are real numbers and a is not zero?

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?