$A = a + {(a - 3) - [(a + 3) - (a - 2)]}$
$= a + [a - 3 - (a + 3 - a + 2)]$
$= a + (a - 3 - a - 3 + a - 2)$
$= a + (a - 8)$
$= a + a - 8$
$= 2a - 8$
$B = [a + (a + 3)] - [(a + 2) - (a - 2)]$
$= (a + a + 3) - (a + 2 - a + 2)$
$= 2a + 3 - 4$
$= 2a - 1$
$=> A < B$