Разложить на множители. ! 1)2a²-2 2)9x³-81x 3)8-72x⁶y² 4)2a²+4ab+2b² 5)5x²+10xy+5y² 6)27a²b²-18ab+3 7)(x²+1)²-4x² 8)4y²-(y-c)²

1)2a²-2=2(a²-1)=2(a-1)(a0+1).
2)9x³-81x=9x(x²-9)=9(x-3)(x+3).
3)8-72x⁶y²=8(1-9x⁶y²)=8(1-3x³y)(1+3x³y).
4)2a²+4ab+2b²=2(a²+2ab+b²)=2(a+b)².
5)5x²+10xy+5y²=5(x²+2xy+y²)=5(x+y)².
6)27a²b²-18ab+3=3(9a²-6ab+1)=3(3ab-1)².
7)(x²+1)²-4x²=(x²+1-2x)(x²+1+2x)=(x-1)²(x+1)².
8)4y²-(y-c)²=(2y-(y-c))(2y+y-c)=(2y-y+c)(3y-c)=(y+c)(3y-c).