sovle the problem or sum
Answers
Step-by-step explanation:
Let x be the number
On dividing x by 3, let y be the quotient and z be the remainder. So, By Euclid's division lemma, we have :
x = 3y + z, where 0 ≤ z < 3
Now,
Cubing both sides :-
(x)³ = (3y + z)³
» x³ = 27y³ + 27y²z + 9yz² + z³ ...... (i) (where 0 ≤ z < 3)
Now,
Case I :-
When z = 0
Substituting value of z on equation (i)
x³ = 27y³
= 9(3q³) = 9m, where m = 3q³
Case II :-
When z = 1
Substituting value of z on equation (i)
x³ = 27y³ + 27y² + 9y + 1
= 9(3y³ + 3y² + y) + 1 = 9m + 1,
where m = 3y³ + 3y² + y
Case III :-
When z = 2
Substituting value of z on equation (i)
x³ = 27y³ + 54y² + 36y + 8
= 9(3y³ + 6y² + 4y) + 8 = 9m + 8,
where m = 3y³ + 6y² + 4y
Hence,
The cube of any positive integer is of the form 9m or 9m + 1 or 9m + 8.
trickyz explaination is superb
n tricky u r
supercalifragilisticeexpialidocious