What is x when 81 divided by x equals 13?

To find the answer, just divide the dividend by the quotient: 81 ÷ 13 = 6.2307692307692

To prove this, let's compute 81 divided by 6.2307692307692: $\frac{81}{6.2307692307692} = 13$

How does it work?

Asking what the value of x could be when 81 divided by x gives a result of 13, is equivalent to solving the following equation:

$\frac{81}{x} = 13$

Multiply both sides by x: $\frac{81 x}{x} = 13 x$
$\frac{81 x}{x}$ is equivalent to $\frac{x}{x} \times 81$ , which simplifies to $1 \times 81$ (or just $81$ ).
Thus, the equation becomes: $81 = 13 x$
To find x, divide both sides by 13: $\frac{81}{13} = \frac{13 x}{13}$
Which gives, after simplification: $6.2307692307692 = x$ (or $x = 6.2307692307692$ )

So, if the dividend is 81 and the quotient is 13, the divisor is 6.2307692307692.