What is x when 57 divided by x equals 3?

To find the answer, just divide the dividend by the quotient: 57 ÷ 3 = 19

To prove this, let's compute 57 divided by 19: $\frac{57}{19} = 3$

How does it work?

Asking what the value of x could be when 57 divided by x gives a result of 3, is equivalent to solving the following equation:

$\frac{57}{x} = 3$

Multiply both sides by x: $\frac{57 x}{x} = 3 x$
$\frac{57 x}{x}$ is equivalent to $\frac{x}{x} \times 57$ , which simplifies to $1 \times 57$ (or just $57$ ).
Thus, the equation becomes: $57 = 3 x$
To find x, divide both sides by 3: $\frac{57}{3} = \frac{3 x}{3}$
Which gives, after simplification: $19 = x$ (or $x = 19$ )

So, if the dividend is 57 and the quotient is 3, the divisor is 19.