А) = 4(а-1)-а²(а-1) = (а-1)(4-а²) = (а-1)(а-1)(а+1) = (а+1)(а-1)²
б) = 3b²(b+1)-3(b+1) = (b+1)(3b²-3) = 3(b-1)(b+1)(b+1) = 3(b-1)(b+1)²
в) = 5c(c²-d²)+10(c²-d²) = (5c+10)(c²-d²) = 5(c+2)(c-d)(c+d)
г) = 3k²(k+1)-3m²(k+1) = (3k²-3m²)(k+1) = 3(k-m)(k+m)(k+1)
д) = 8(x-1)-x³(x-1) = (x-1)(8-x³) = (x-1)(2-x)(4+2x+x²)
е) = y³(y+2)+27(y+2) = (y+2)(y³+27) = (y+2)(y+3)(y²-3y+9)
Дальше не знаю.