What is the value of the expression $(37 + 12)^2 - (37^2 +12^2)$?
I notice that this expression has the form $(a + b)^2 - (a^2 + b^2)$, where $a = 37$ and $b = 12$. I also recall that there is an identity that says $(a + b)^2 = a^2 + 2ab + b^2$. Using this identity, I can rewrite the expression as $(a^2 + 2ab + b^2) - (a^2 + b^2)$. Simplifying, I get $2ab$. Substituting the values of $a$ and $b$, I get $2 \times 37 \times 12$. Multiplying, I get $888$. 