Find the HCF of (4315 − 1) and (425 − 1).

1 (425 − 1) 1024 1023

1023

HCF(315, 25) = 5 According to the concept, HCF {(4315 − 1), (425 − 1)}  = (4HCF(315, 25) − 1) = (45 − 1) = 1024 − 1 = 1023