Объяснение:
1.
1) (56x³y⁴)/z⁵ ·(-(x²z⁴)/(16y⁶))=56/(-16) ·x³⁺²y⁴⁻⁶z⁻⁵⁺⁴=-7/2 ·x⁵y⁻²z⁻¹=(-7x⁵)/(2y²z)
2) (72a⁷b¹⁶)/c¹⁰ ÷(24a³b¹⁶c⁸)=72/24 ·a⁷⁻³b¹⁶⁻¹⁶c⁻¹⁰⁻⁸=3a⁴b⁰c⁻¹⁸=(3a⁴)/c¹⁸
3) (3b-3c)/c ·(4c²)/(b²-c²)=(3(b-c)·4c)/((b-c)(b+c))=(12c)/(b+c)
2.
1) ((m+7)/m -(n+7)/n)·(mn)/(m²-n²)=(mn+7n-mn-7m)/mn ·(mn)/(m²-n²)=(-7(m-n))/((m-n)(m+n))=-7/(m+n)
2) (a-2)/a² ·(ab-a)/(a-2) +(2-b)/(2a)=(a(b-1))/a² +(2-b)/(2a)=(b-1)/a +(2-b)/(2a)=(2b-2+2-b)/(2a)=b/(2a)
