Question

What is the cubic root of 81 without a calculator? And how do you get it? Please explain

Answer 1

Answer:

$3\sqrt[3]{3}$

Step-by-step explanation:

First, notice that 81 is divisible by 3.

81/3 = 27

27 is also divisible by 3.

27/3 = 9

9 = 3 * 3

81 = 3 * 3 * 3 * 3

81 = 3^3 * 3

$\sqrt[3]{81} = \sqrt[3]{3^3 \times 3} = 3\sqrt[3]{3}$