What is x when 51 divided by x equals 17?

To find the answer, just divide the dividend by the quotient: 51 ÷ 17 = 3

To prove this, let's compute 51 divided by 3: $\frac{51}{3} = 17$

How does it work?

Asking what the value of x could be when 51 divided by x gives a result of 17, is equivalent to solving the following equation:

$\frac{51}{x} = 17$

Multiply both sides by x: $\frac{51 x}{x} = 17 x$
$\frac{51 x}{x}$ is equivalent to $\frac{x}{x} \times 51$ , which simplifies to $1 \times 51$ (or just $51$ ).
Thus, the equation becomes: $51 = 17 x$
To find x, divide both sides by 17: $\frac{51}{17} = \frac{17 x}{17}$
Which gives, after simplification: $3 = x$ (or $x = 3$ )

So, if the dividend is 51 and the quotient is 17, the divisor is 3.