If $A\ \spadesuit\ B$ is defined as $A\ \spadesuit\ B = A + B + 4$, what is the value of $A$ for which $A\ \spadesuit\ 2 = 19$?
So, I can rewrite the equation as $A + 2 + 4 = 19$. Simplifying, I get $A + 6 = 19$. Subtracting 6 from both sides, I get $A = 19 - 6$. Therefore, $A = 13$. 