Упростите a²-4a+4/a²+6a+9*2a²-18/12-6a

a²-4a+4/a²+6a+9*2a²-18/12-6a = (a-2)²/(a+3)² * 2(a-3)(a+3)/6(2-a) = - (a-2)/(a+3) * (a-3)/3 =   - (a-2)(a-3)/3(a+3)