What is x when 87 divided by x equals 40?

To find the answer, just divide the dividend by the quotient: 87 ÷ 40 = 2.175

To prove this, let's compute 87 divided by 2.175: $\frac{87}{2.175} = 40$

How does it work?

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

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

Multiply both sides by x: $\frac{87 x}{x} = 40 x$
$\frac{87 x}{x}$ is equivalent to $\frac{x}{x} \times 87$ , which simplifies to $1 \times 87$ (or just $87$ ).
Thus, the equation becomes: $87 = 40 x$
To find x, divide both sides by 40: $\frac{87}{40} = \frac{40 x}{40}$
Which gives, after simplification: $2.175 = x$ (or $x = 2.175$ )

So, if the dividend is 87 and the quotient is 40, the divisor is 2.175.