What is x when 45 divided by x equals 87?

To find the answer, just divide the dividend by the quotient: 45 ÷ 87 = 0.51724137931034

To prove this, let's compute 45 divided by 0.51724137931034: $\frac{45}{0.51724137931034} = 87$

How does it work?

Asking what the value of x could be when 45 divided by x gives a result of 87, is equivalent to solving the following equation:

$\frac{45}{x} = 87$

Multiply both sides by x: $\frac{45 x}{x} = 87 x$
$\frac{45 x}{x}$ is equivalent to $\frac{x}{x} \times 45$ , which simplifies to $1 \times 45$ (or just $45$ ).
Thus, the equation becomes: $45 = 87 x$
To find x, divide both sides by 87: $\frac{45}{87} = \frac{87 x}{87}$
Which gives, after simplification: $0.51724137931034 = x$ (or $x = 0.51724137931034$ )

So, if the dividend is 45 and the quotient is 87, the divisor is 0.51724137931034.