71 = 772 = 4973 = 34374 = 240175 = 16807So, from this we know unit places are REPEATING in order 7, 9, 3 and 1So, from this we can GENERALIZE a formulaIf Number is 74n – 3 then unit place is 774n – 2 then unit place is 974n – 1 then unit place is 374n then unit place is 1For all n ≥ 1So, 73 can be written as 4 × 19 – 3So, unit place is 7