Answer:
Given:
[tex] \boxed{ \mathsf{F = \frac{mn}{d} }}[/tex]
Divide both sides by "mn":
[tex] \mathsf{ \frac{F}{mn} = \frac{mn}{d \times mn} }[/tex]
The two mn's on the RHS gets canceled out. So we're left with:
[tex] \mathsf{ \frac{F}{mn} = \frac{1}{d} }[/tex]
Invert the fractions present on either side of the "equals" sign
(In other words, flip it on its head so its numerator becomes its denominator and vice):
[tex] \mathsf{ \frac{mn}{F} = \frac{d}{1} }[/tex]
Hence, we got the value of d:
[tex] \underline{\mathsf{ d= \frac{mn}{F} }}[/tex]
