-9a^2+[2a^2-2(a-3a^2)+5a]
=-9a^2+[2a^2-2a+6a^2+5a]
=-9a^2+[8a^2+3a]
=-9a^2+8a^2+3a
=-a^2+3a
=-(-2)^2+3*(-2)
=-4-6
=-10