What is x when 78 divided by x equals 31?

To find the answer, just divide the dividend by the quotient: 78 ÷ 31 = 2.5161290322581

To prove this, let's compute 78 divided by 2.5161290322581: $\frac{78}{2.5161290322581} = 31$

How does it work?

Asking what the value of x could be when 78 divided by x gives a result of 31, is equivalent to solving the following equation:

$\frac{78}{x} = 31$

Multiply both sides by x: $\frac{78 x}{x} = 31 x$
$\frac{78 x}{x}$ is equivalent to $\frac{x}{x} \times 78$ , which simplifies to $1 \times 78$ (or just $78$ ).
Thus, the equation becomes: $78 = 31 x$
To find x, divide both sides by 31: $\frac{78}{31} = \frac{31 x}{31}$
Which gives, after simplification: $2.5161290322581 = x$ (or $x = 2.5161290322581$ )

So, if the dividend is 78 and the quotient is 31, the divisor is 2.5161290322581.