How do you know when to put an open or closed circle when graphing inequalities?

After the seventh month of a 12-month loan: the numerator is: {(n + 11) + (n + 10) + (n + 9) + (n + 8) + (n + 7) + (n + 6) + (n + 5)} = , and the denominator is: {(n) + (n + 1) + + (n + 11)} = . therefore, the fraction is numerator/denominator (to the nearest tenth) = %

Can someone me with this problem i don't understand i need

What is the equation of this graphed line? enter your answer in slope-intercept form in the box.