(a/(a-c)+2ac/(a^2-2ac+c^2 /(a+c)-a-c) выражение

1)a/(a-c)+2ac/(a-c)²=(a²-ac+2ac)/(a-c)²=(a²+ac)/(a-c)²=a(a+c)/(a-c)²
2)4ac/(a+c)-(a+c)=(4ac-a²-2ac-c²)/(a+c)=-(a-c)²/(a+c)
3)a(a+c)/(a-c)²*[-(a-c)²/(a+c)]=-a