What is x when 39 divided by x equals 5?

To find the answer, just divide the dividend by the quotient: 39 ÷ 5 = 7.8

To prove this, let's compute 39 divided by 7.8: $\frac{39}{7.8} = 5$

How does it work?

Asking what the value of x could be when 39 divided by x gives a result of 5, is equivalent to solving the following equation:

$\frac{39}{x} = 5$

Multiply both sides by x: $\frac{39 x}{x} = 5 x$
$\frac{39 x}{x}$ is equivalent to $\frac{x}{x} \times 39$ , which simplifies to $1 \times 39$ (or just $39$ ).
Thus, the equation becomes: $39 = 5 x$
To find x, divide both sides by 5: $\frac{39}{5} = \frac{5 x}{5}$
Which gives, after simplification: $7.8 = x$ (or $x = 7.8$ )

So, if the dividend is 39 and the quotient is 5, the divisor is 7.8.