Say we have the equilibrium $$\ce{A_{(aq)} + 2B_{(aq)} <=> C_{(aq)} + D_{(aq)}}$$ meaning the formula for the equilibrium constant is $$\ce{K_{c} = \frac{[C][D]}{[A][B]^2}}$$ My understanding is that adding more water would shift the equilibrium to the left (in the same way that decreasing the pressure would shift the equilibrium to the left if it was a gaseous equilibrium).
Why is this the case? What mathematically (using the equation) and physically (in terms of kinetics?) means that $\ce{[A]}$ and $\ce{[B]}$ must increase?
And why does the equilibrium constant remain the same?
Apologies if this is a duplicate, but I couldn't find a specific answer to this question.
Many thanks!