What is x when 51 divided by x equals 64?

To find the answer, just divide the dividend by the quotient: 51 ÷ 64 = 0.796875

To prove this, let's compute 51 divided by 0.796875: $\frac{51}{0.796875} = 64$

How does it work?

Asking what the value of x could be when 51 divided by x gives a result of 64, is equivalent to solving the following equation:

$\frac{51}{x} = 64$

Multiply both sides by x: $\frac{51 x}{x} = 64 x$
$\frac{51 x}{x}$ is equivalent to $\frac{x}{x} \times 51$ , which simplifies to $1 \times 51$ (or just $51$ ).
Thus, the equation becomes: $51 = 64 x$
To find x, divide both sides by 64: $\frac{51}{64} = \frac{64 x}{64}$
Which gives, after simplification: $0.796875 = x$ (or $x = 0.796875$ )

So, if the dividend is 51 and the quotient is 64, the divisor is 0.796875.