1) a²+6a-b²+4b+5=(a²+2*3*a+9)-b²+4*b-4=(a²+2*3*a+3²)-(b²-2*2b+2²)=
=(a+3)²-(b-2)²=(a+3+b-2)(a+3-b+2)=(a+b+1)(a-b+5).
2) 9x⁴-3x²+1=9x⁴-3x²+9x²-9x²+1=9x⁴+6x²+1-9x²=(3x²)²+2*3x*1+1-(3x)²=
=(3x²+1)²-(3x)²=(3x²+1+3x)(3x²+1-3x)=(3x²+3x+1)(3x²-3x+1)=
=3*(x²+x+1/3)*3*(x²-x+1/3)=9*(x²+x+1/3)*(x²-x+1/3).