Defining BCA as the balance on the current account, BKA as the balance on the capital account, and BRA as balance on the reserve account, the balance of

payments identity is:

BCA$+$BKA$=0$

BCA$-$BKA$+$BRA$=0$

BCA$+$BKA$-$BRA$=0$

BCA$+$BKA$+$BRA$=0$