Упростите выражения:

(2a-5) ^2-5 (4a+5)

(b-4^2) - (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)