What is x when 81 divided by x equals 25?

To find the answer, just divide the dividend by the quotient: 81 ÷ 25 = 3.24

To prove this, let's compute 81 divided by 3.24: $\frac{81}{3.24} = 25$

How does it work?

Asking what the value of x could be when 81 divided by x gives a result of 25, is equivalent to solving the following equation:

$\frac{81}{x} = 25$

Multiply both sides by x: $\frac{81 x}{x} = 25 x$
$\frac{81 x}{x}$ is equivalent to $\frac{x}{x} \times 81$ , which simplifies to $1 \times 81$ (or just $81$ ).
Thus, the equation becomes: $81 = 25 x$
To find x, divide both sides by 25: $\frac{81}{25} = \frac{25 x}{25}$
Which gives, after simplification: $3.24 = x$ (or $x = 3.24$ )

So, if the dividend is 81 and the quotient is 25, the divisor is 3.24.