+0  
 
+1
78
1
avatar+266 

Please give me a detailed solution for the question

Let n > 18 be a positive integer such that n-1 and n+1 both are prime .

Prove that n has at least 8 different positive factors .

 Nov 9, 2018
 #1
avatar
0

42 =2 x 3 x 7 =3 "Prime Factors"
Total divisors =The exponent of each "Prime Factor" + 1, all multiplied together: (1+1) x (1+1)x(1+1) =8 divisors:
1 | 2 | 3 | 6 | 7 | 14 | 21 | 42 (8 divisors), or factors.
42 - 1 =41 Prime number
42+1 =43 Prime number.

 Nov 9, 2018
edited by Guest  Nov 9, 2018

17 Online Users

avatar
avatar

New Privacy Policy

We use cookies to personalise content and advertisements and to analyse access to our website. Furthermore, our partners for online advertising receive information about your use of our website.
For more information: our cookie policy and privacy policy.