What is x when 12 divided by x equals 78?

To find the answer, just divide the dividend by the quotient: 12 ÷ 78 = 0.15384615384615

To prove this, let's compute 12 divided by 0.15384615384615: $\frac{12}{0.15384615384615} = 78$

How does it work?

Asking what the value of x could be when 12 divided by x gives a result of 78, is equivalent to solving the following equation:

$\frac{12}{x} = 78$

Multiply both sides by x: $\frac{12 x}{x} = 78 x$
$\frac{12 x}{x}$ is equivalent to $\frac{x}{x} \times 12$ , which simplifies to $1 \times 12$ (or just $12$ ).
Thus, the equation becomes: $12 = 78 x$
To find x, divide both sides by 78: $\frac{12}{78} = \frac{78 x}{78}$
Which gives, after simplification: $0.15384615384615 = x$ (or $x = 0.15384615384615$ )

So, if the dividend is 12 and the quotient is 78, the divisor is 0.15384615384615.