Question

Proof that if a number is doubled than its cube is 8 timed

Answer 1

let the number be 'n';

cube of the number is n^3=a;

if it is doubled i.e 2n

(2n)^3=(2^3)*(n^3);

=8*(n^3)

=8*a

therefore if a number is doubled then its cube is 8 timed

Answer 2

Let x be the number

⇒ the cube of the number = x³

when the number is double:

number = 2x

cube of the number = (2x)³ = 8x³

Find the number of times of x³ is 8x³:

Number of times = 8x³/x³ = 8 times (proved)