Aprofessional lawn care service can mow 2 3/4 acres of lawn in one hour. how many hours would it take them to mow the lawn that is 6 7/8 acres?

  example you can find the perimeter by addig all of its respective sides as such: (12+x)+(12+x)+(7+y)+(7+y).  adding like terms will result in   2x+2y+38    if you chose  xy+7x+12y+84, you multiplied the two sides to find the area.  if you chose  x+y+19

This seems very interesting. i think i can !