Question

write the cubes of 4 natural numbers which are multiples of 3 and verify that "The cube of a natural number which is a multiple of 3 is a multiple of 27"

Answer 1

consider y is a multiple of 3
so y=3x(x is a natural number)
now
${y}^{3} = (3x) {}^{3} = {3}^{3} {x}^{3} = 27 {x}^{3}$
which is multiple of 27

Answer 2

Let x be multiple of 3

Now Y= 3x ( 3 × x for multiplicating 3 times)

Y^3= (3x)^3

Y^3=27x^3

This prooves that the cube of a natural number which is a multiple of 3 is a multiple of 27