A: For the reaction $A_{\left(g\right)}\rightleftharpoons B_{\left(g\right)}+C_{\left(g\right),}{K}_p=1atm.$If we start with equal moles of all gases at 9 atm of initial pressure, then at equilibrium, partial pressure of A increases.
R:   Reaction quotient  $Q_p>K_p$. Hence equilibrium shifts in backward direction.