№1
а) a³-2a²+18-9a = a³-9a-2a²+18 = a(a²-9)-2(a²-9) = (a-2)(a²-9)
б) a^5b²+27a²b^5 = a²*a³*b²+27*a²*b²*b³ = a²b²(a³+27b³)
№2
а) (3x+1)(x-1)-(3x-1)(3x+1) = 3x²-3x+x-1-(9x²+3x-3x-1) = 3x²-2x-1-(9x²-1) =
= 3x²-2x-1-9x²+1=-6x²-2x
б) (2a+2b)²-2(a+b)² = 4a²+2*2a*2b+4b²-2(a²+2ab+b²) = 4a²+8ab+4b²-2a²-4ab-2b² = 2a²+4ab+2b²