What is x when 90 divided by x equals 42?

To find the answer, just divide the dividend by the quotient: 90 ÷ 42 = 2.1428571428571

To prove this, let's compute 90 divided by 2.1428571428571: $\frac{90}{2.1428571428571} = 42$

How does it work?

Asking what the value of x could be when 90 divided by x gives a result of 42, is equivalent to solving the following equation:

$\frac{90}{x} = 42$

Multiply both sides by x: $\frac{90 x}{x} = 42 x$
$\frac{90 x}{x}$ is equivalent to $\frac{x}{x} \times 90$ , which simplifies to $1 \times 90$ (or just $90$ ).
Thus, the equation becomes: $90 = 42 x$
To find x, divide both sides by 42: $\frac{90}{42} = \frac{42 x}{42}$
Which gives, after simplification: $2.1428571428571 = x$ (or $x = 2.1428571428571$ )

So, if the dividend is 90 and the quotient is 42, the divisor is 2.1428571428571.