# The binary operation □ is defined as a + b = ab+(a+b), where a and b are any two real numbers. The value of the identity element of this operation, defined as the number x such that a □ x = a, for any a, is ?

$x = 0$
If $a \square x = a$ then $a x + a + x = a$ or
$\left(a + 1\right) x = 0$ If this should occur for all $a$ then $x = 0$