Explanation:
Ag+(aq) + 2NH3 (aq) ⇄ Ag(NH3)2 (aq)
When it comes to question of this sort, the LeChatelier principle should come to mind. The LeChatelier principle states that changes in the temperature, pressure, volume, or concentration of a system will result in predictable and opposing changes in the system in order to achieve a new equilibrium state.
increasing the concentration of Ag+
This would lead to an increase in concentration of reactants, the system would annul or oppose this change by moving towrds the right, favouring the forward reaction.
decreasing the concentration of NH3
This would lead to a decrease in concentration of reactants, the system would annul this change by moving to the left, favourin the backward reaction.
increasing the concentration of Ag(NH3)2
This would lead to an increase in concnetration of products, the system would annul or oppose this change by moving towards the left, favouring the backward reaction.