2
a)a³-2a²+18-9a=a²(a-2)-9(a-2)=(a-2)(a²-9)=(a-2)(a-3)(a+3)
б)a^5b²+27a²b^5=a²b²(a³+27b³)=a²b²(a+3b)(a²-3ab+9b²)
3
a)(3x+1)(x-1)-(3x-1)(3x+1)=(3x+1)(x-1-3x+1)=(3x+1)(-2x)=-6x²-2x
б)(2a+2b)²-2(a+b)²=4(a+b)²-2(a+b)²=2(a_b)²
4
(4a+1)²(4a-1)²-(16a²+1)=-64a²
(4a+1)²(4a-1)²-(16a²+1)²=(16a²-1)² - (16a²+1)²=(16a²-1-16a²-1)(16a²-1+16a²+1)=
=-2*32a²=-64a²