1、2a(a+b)-(a+b)²
=2a²+2ab-a²-2ab-b²
=a²-b²
=(√2012)²-(√2013)²
=2012-2013
=-1
2、(√x+12)²-(√x+2)²
=(x+12)-(x+2)
=x+12-x-2
=10