Question

(3×x)³=81
find the value of x​

Answer 1

Question : (3x)³=81

Answer :

${27x}^{3} = 81$

as we know when cube goes from on side to other then

$27x = \sqrt[3]{81}$

by splitting cube root 81

$27x = \sqrt[3]{9 \times 9}$

also

$27x = \sqrt[3]{3 \times 3 \times 3 \times 3}$

so

$24x = 3\sqrt[3]{3}$

then

$x = 3\sqrt[3]{3} \div 24$

$x = \frac{ \sqrt[3]{3} }{8}$

there is your answer

Answer 2

Step-by-step explanation:

${(3x)}^{3} = 81 \\ 3x \times 3x \times 3x = 81 \\ 27 {x}^{3} = 81 \\ {x}^{3} = \frac{81}{27} \\ {x}^{3} = 3 \\ {x}^{3} = {(\sqrt[3]{3} )}^{3} \\ x = \sqrt[3]{3}$