What is x when 81 divided by x equals 19?

To find the answer, just divide the dividend by the quotient: 81 ÷ 19 = 4.2631578947368

To prove this, let's compute 81 divided by 4.2631578947368: $\frac{81}{4.2631578947368} = 19$

How does it work?

Asking what the value of x could be when 81 divided by x gives a result of 19, is equivalent to solving the following equation:

$\frac{81}{x} = 19$

Multiply both sides by x: $\frac{81 x}{x} = 19 x$
$\frac{81 x}{x}$ is equivalent to $\frac{x}{x} \times 81$ , which simplifies to $1 \times 81$ (or just $81$ ).
Thus, the equation becomes: $81 = 19 x$
To find x, divide both sides by 19: $\frac{81}{19} = \frac{19 x}{19}$
Which gives, after simplification: $4.2631578947368 = x$ (or $x = 4.2631578947368$ )

So, if the dividend is 81 and the quotient is 19, the divisor is 4.2631578947368.