What is x when 87 divided by x equals 7?

To find the answer, just divide the dividend by the quotient: 87 ÷ 7 = 12.428571428571

To prove this, let's compute 87 divided by 12.428571428571: $\frac{87}{12.428571428571} = 7$

How does it work?

Asking what the value of x could be when 87 divided by x gives a result of 7, is equivalent to solving the following equation:

$\frac{87}{x} = 7$

Multiply both sides by x: $\frac{87 x}{x} = 7 x$
$\frac{87 x}{x}$ is equivalent to $\frac{x}{x} \times 87$ , which simplifies to $1 \times 87$ (or just $87$ ).
Thus, the equation becomes: $87 = 7 x$
To find x, divide both sides by 7: $\frac{87}{7} = \frac{7 x}{7}$
Which gives, after simplification: $12.428571428571 = x$ (or $x = 12.428571428571$ )

So, if the dividend is 87 and the quotient is 7, the divisor is 12.428571428571.