What is x when 31 divided by x equals 8?

To find the answer, just divide the dividend by the quotient: 31 ÷ 8 = 3.875

To prove this, let's compute 31 divided by 3.875: $\frac{31}{3.875} = 8$

How does it work?

Asking what the value of x could be when 31 divided by x gives a result of 8, is equivalent to solving the following equation:

$\frac{31}{x} = 8$

Multiply both sides by x: $\frac{31 x}{x} = 8 x$
$\frac{31 x}{x}$ is equivalent to $\frac{x}{x} \times 31$ , which simplifies to $1 \times 31$ (or just $31$ ).
Thus, the equation becomes: $31 = 8 x$
To find x, divide both sides by 8: $\frac{31}{8} = \frac{8 x}{8}$
Which gives, after simplification: $3.875 = x$ (or $x = 3.875$ )

So, if the dividend is 31 and the quotient is 8, the divisor is 3.875.