Reuben is putting money into a savings account. He starts with $$650$ in the savings account, and each week he adds $$40.$

Let $S$ represent the total amount of money in the savings account $($in dollars$),$ and let $W$ represent the number of weeks Reuben has been adding money. Write an equation relating $S$ to $W.$ Then use this equation to find the total amount of money in the savings account after $19$ weeks.

Equation:

Total amount of money after $19$ weeks: