What is x when 40 divided by x equals 87?

To find the answer, just divide the dividend by the quotient: 40 ÷ 87 = 0.45977011494253

To prove this, let's compute 40 divided by 0.45977011494253: $\frac{40}{0.45977011494253} = 87$

How does it work?

Asking what the value of x could be when 40 divided by x gives a result of 87, is equivalent to solving the following equation:

$\frac{40}{x} = 87$

Multiply both sides by x: $\frac{40 x}{x} = 87 x$
$\frac{40 x}{x}$ is equivalent to $\frac{x}{x} \times 40$ , which simplifies to $1 \times 40$ (or just $40$ ).
Thus, the equation becomes: $40 = 87 x$
To find x, divide both sides by 87: $\frac{40}{87} = \frac{87 x}{87}$
Which gives, after simplification: $0.45977011494253 = x$ (or $x = 0.45977011494253$ )

So, if the dividend is 40 and the quotient is 87, the divisor is 0.45977011494253.