Объяснение:
1.
1) a-(a²+x²)/(a+x)=(a*(a+x)-a²-x²)/(a+x)=(a²+ax-a²-x²)/(a+x)=
=(ax-x²)/(a+x)=a*(a-x)/(a+x).
2) (2a/x)+4a/(a-x)=(2a*(a-x)+4a*x)/(x*(a-x))=(2a²-2ax+4ax)/(x*(a-x))=
=(2a²+2ax)/(x*(a-x))=2a*(a+x)/(x*(a-x)).
3) (x*(a-x)/(a+x))*(2a*(a+x)/(x*(a-x))=x*(a-x)*2a*(a+x)/((a+x)*x*(a-x)=2a.
2.
1) (am²-an²)/(m²+2mn+n²)=a*(m²-n²)/(m+n)²=
=a*(m+n)(n-n)/(m+n)²=a*(m-n)/(m+n).
2)(am²-2amn+an²)/(3m+3n)=a*(m²-2mn+n²)/(3*(m+n))=
=a*(m-n)²/(3*(m+n)).
3) (a*(m-n)/(m+n)):(a*(m-n)²/(3*(m+n)=a*(m-n)*3*(m+n)/((m+n)(a*(m-n)²)=
=3/(m-n).
Объяснение:
1.
1) a-(a²+x²)/(a+x)=(a*(a+x)-a²-x²)/(a+x)=(a²+ax-a²-x²)/(a+x)=
=(ax-x²)/(a+x)=a*(a-x)/(a+x).
2) (2a/x)+4a/(a-x)=(2a*(a-x)+4a*x)/(x*(a-x))=(2a²-2ax+4ax)/(x*(a-x))=
=(2a²+2ax)/(x*(a-x))=2a*(a+x)/(x*(a-x)).
3) (x*(a-x)/(a+x))*(2a*(a+x)/(x*(a-x))=x*(a-x)*2a*(a+x)/((a+x)*x*(a-x)=2a.
2.
1) (am²-an²)/(m²+2mn+n²)=a*(m²-n²)/(m+n)²=
=a*(m+n)(n-n)/(m+n)²=a*(m-n)/(m+n).
2)(am²-2amn+an²)/(3m+3n)=a*(m²-2mn+n²)/(3*(m+n))=
=a*(m-n)²/(3*(m+n)).
3) (a*(m-n)/(m+n)):(a*(m-n)²/(3*(m+n)=a*(m-n)*3*(m+n)/((m+n)(a*(m-n)²)=
=3/(m-n).