Final answer:
The expression for the current through the battery is Current_through_battery = Current_blue + Current_red = 1.4 A.
Step-by-step explanation:
In order to write an expression for the current through the battery, we need to consider the circuit configuration and the voltage across the battery. Let's assume that the voltage across the battery is denoted as V.
Based on the given information, the current going through the battery must be the sum of the currents from the red branch and the blue branch, which is equal to 1.4 A. Therefore, the expression for the current through the battery is:
Current_through_battery = Current_blue + Current_red = 1.4 A