To represent the total change to John's account for the transactions he made, we need to consider how each transaction affects his account balance.
- Withdrawing $55 from the ATM means his account decreases by $55. This can be represented as -$55.
- Writing a check for $18 means his account decreases by $18 as well. This can be represented as -$18.
To find the total change to John's account, we sum these changes:
\[ -55 + (-18) \]
This simplifies to:
\[ -55 - 18 = -73 \]
Thus, the equation that represents the total change to John's account for these two transactions is:
\[ -55 + (-18) = -73 \]
Therefore, the correct response is:
\[ -55 + (-18) = -73 \]