Here, M is the money supply, V is the velocity of money, P is the price level, and Q is the real quantity of goods and services.
It's easy to see that if M increases and Q increases the same amount, then if V is constant, P will also hold constant.
Or if Q is constant and a decrease in V offsets the increase in M, P will again hold constant.
Increasing the money supply by printing money does not automatically cause prices to increase, because there are other variables in the equation.