Okay. In order for Chris to reach is goal, he needs to change the amount he saves, which is the 20x. This is because 20 * 4 is 80, which will only get him up to $180, including what is in his savings account. 180 < 300.
How to find the real answer:
Alright. So we already know that Chris wants to have $300 in his savings account in 4 months, and already has $100 in the account. The way we could set up the equation is this: 300 = 4x + 100. First, subtract 100 from both sides to get 200 = 4x. Divide 4 from both sides to isolate the variable and you get x = 50. To me this goal, Chris would have to save $50 each month. He would have to change the coefficient (the number right before the variable) in the equation, so it would become this: T = 50x + 100.
