1)х³-8у³=(x-2y)(x²+2y+4y²)
2)c²-4c+4-9x²=(c²-4c+4)-9x²=(c-2)²-(3x)²=(c-2-3x)(c-2+3x)
3)4c²+20c+25-9a²=(4c²+20c+25)-9a²=(2c+5)²-(3a)²=(2c+5-3a)(2c+5+3a)
4)3x²+2x-xy-2y²+y³-3xy²=3x²-3xy²+2x-2y²-xy+y³=3x(x-y²)+2(x-y²)-y(x-y²)=(x-y²)(3x+2-y)
5)a²x+a+ax²+x+2ax+2=(a²x+ax²+2ax) +(a+x+2)=ax(a+x+2)+(a+x+2)=(a+x+2)(ax+1)