What is x when 40 divided by x equals 12?

To find the answer, just divide the dividend by the quotient: 40 ÷ 12 = 3.3333333333333

To prove this, let's compute 40 divided by 3.3333333333333: $\frac{40}{3.3333333333333} = 12$

How does it work?

Asking what the value of x could be when 40 divided by x gives a result of 12, is equivalent to solving the following equation:

$\frac{40}{x} = 12$

Multiply both sides by x: $\frac{40 x}{x} = 12 x$
$\frac{40 x}{x}$ is equivalent to $\frac{x}{x} \times 40$ , which simplifies to $1 \times 40$ (or just $40$ ).
Thus, the equation becomes: $40 = 12 x$
To find x, divide both sides by 12: $\frac{40}{12} = \frac{12 x}{12}$
Which gives, after simplification: $3.3333333333333 = x$ (or $x = 3.3333333333333$ )

So, if the dividend is 40 and the quotient is 12, the divisor is 3.3333333333333.