Выражения: (2a-5)^2-5(4a+5) (b--1)(b-2) m / (1-m^2)+1 / (1-m) 2m/(m-4) - 5m-2 / (m^2-16)

(2a-5)^2-5(4a+5)=4a²-20a+25-20a-25=4a²-40a
(b-4^2)-(b-1)(b-2)=b²-8b+16-b²+2b+b-2=-5b+14
m / (1-m^2)+1 / (1-m)=m/(1-m)(1+m)+1/(1-m)=(m+1+m)/(1-m²)=(1+2m)/(1-m²)
2m/(m-4) - 5m-2 / (m^2-16)=2m/(m-4) -(5m-2)/(m-4)(m+4)=
=(2m²+8m-5m+2)/(m²-16)=(2m²+3m+2)/(m²-16)