If the graphs of the linear equations in a system are parallel, what does that mean about the possible solution(s) of the system?
a.
there are infinitely many solutions.
b.
there is exactly one solution
c.
the lines in a system cannot be parallel
d.
there is no solution

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?