What is x when 54 divided by x equals 12?

To find the answer, just divide the dividend by the quotient: 54 ÷ 12 = 4.5

To prove this, let's compute 54 divided by 4.5: $\frac{54}{4.5} = 12$

How does it work?

Asking what the value of x could be when 54 divided by x gives a result of 12, is equivalent to solving the following equation:

$\frac{54}{x} = 12$

Multiply both sides by x: $\frac{54 x}{x} = 12 x$
$\frac{54 x}{x}$ is equivalent to $\frac{x}{x} \times 54$ , which simplifies to $1 \times 54$ (or just $54$ ).
Thus, the equation becomes: $54 = 12 x$
To find x, divide both sides by 12: $\frac{54}{12} = \frac{12 x}{12}$
Which gives, after simplification: $4.5 = x$ (or $x = 4.5$ )

So, if the dividend is 54 and the quotient is 12, the divisor is 4.5.