What is x when 21 divided by x equals 23?

To find the answer, just divide the dividend by the quotient: 21 ÷ 23 = 0.91304347826087

To prove this, let's compute 21 divided by 0.91304347826087: $\frac{21}{0.91304347826087} = 23$

How does it work?

Asking what the value of x could be when 21 divided by x gives a result of 23, is equivalent to solving the following equation:

$\frac{21}{x} = 23$

Multiply both sides by x: $\frac{21 x}{x} = 23 x$
$\frac{21 x}{x}$ is equivalent to $\frac{x}{x} \times 21$ , which simplifies to $1 \times 21$ (or just $21$ ).
Thus, the equation becomes: $21 = 23 x$
To find x, divide both sides by 23: $\frac{21}{23} = \frac{23 x}{23}$
Which gives, after simplification: $0.91304347826087 = x$ (or $x = 0.91304347826087$ )

So, if the dividend is 21 and the quotient is 23, the divisor is 0.91304347826087.