standard_description: Solve real-world and mathematical problems by graphing points in all four quadrants of the coordinate plane. Include use of coordinates and absolute value to find distances between points with the same first coordinate or the same second coordinate.
problem_activity: Task
At the beginning of January, Susita had some money in her checking account.  At the end of each month she deposits enough to double the amount currently in the account. However, she has a loan to pay off, requiring her to withdraw \$10 from the account monthly (immediately after her deposit).
Assuming January is the first month, write an equation that describes the amount of money in Susita’s account at the end of the $n^{\rm th}$ month, $S(n)$, in terms of the amount of money in Susita’s account at the end of the $(n-1)^{\rm th}$ month, $S(n-1)$.
At the end of May, Susita had \$2 left in the account.  How much did she have at the end of January?


aligns: no