Jade had $300 in her checking account. Each week, she Jade spends $15 dollars. Let x represent the number of months and f(x) represent Jade's account balance.

A. Determine the linear relationship to this algebraic model in slope-intercept form.

B. Determine how much money Jade has left in her checking account after 6 weeks.

C. If Jade has $180 left in her checking out, determine the number of weeks have passed.