Ramon. wants to balance his checking account. he has a $2340 in the account. he writes a check for $140. he posits a check for $268. how much does ramon have left in his checking account

So,

There are two transactions in Ramon's account.  He first withdraws $140 (the check) and then deposits $268.  We can write this as an expression.

2340 - 140 + 268

Simplify.
2200 + 268
2468

Ramon has $2468 left in his checking account.