Final answer:
To write the second equation, we consider the savings account. After t months, the amount in Simon's savings account can be calculated as $1,000 + $600t.
Step-by-step explanation:
To write the second equation in the system, we need to consider the savings account. Simon plans to deposit $600 every month into his savings account. Let's represent the number of months as 't'. So, after t months, the amount in his savings account can be calculated as:
Savings Account = $1,000 + $600t