Find the value of each of the following using the short-cut method: (47) 3

Find the value of each of the following using the short-cut method:
(47)³

Let’s take, a = 4 and b = 7

So, by using the formula,

We have, a³ + 3a²b + 3ab² + b³

16

4

16

× 21

49

× 12

49

× 7

64

+39

336

+62

588

+34

343

103

398

622

By taking the highlighted digits only,

We get;

؞(47)³ = 103823

2