let a be any +ve integer b=6
by euclid 's division lemma,
a=bq+r, 0=< r < b a= 6q+r,0=< r
when
r=0,a = 6q= (6q)3 ---> a3 = 216q3 =6(36q3)=6q(where m is = 6q3 )
by similar manner you can prove for
r=1,2,3,4,5 and you will get the proof
Question 1 Show that the cube of a positive integer of the form 6q + r, where q is an integer and r = 0, 1, 2, 3, 4, 5 is also of the form 6m + r.
Show that any positive even integer can be written in the form 6q,6q+2 and 6q+4 where q is an integer