( 737 + 6 × a ) - 16 × 13 = 535
( 737 + 6 × a ) - 208 = 535
737 + 6 × a = 535 + 208
737 + 6 × a = 743
6 × a = 743 - 737
6 × a = 6
a = 6 : 6
a = 1 → numarul, aflat prin metoda mersului invers
