1)a^3-24a^2b+44ab^2
=a(a^2-24ab+44b^2)
=a(a-22b)(a-2b)
2)6x^2+23xy+20y^2
=(2x+5y)(3x+4y)
3)a^6-9a^3+8
=(a^3-8)(a^3-1)
=(a-2)(a^2+4a+4)(a-1)(a^2+a+1)
=(a-2)(a^2+2a+4)(a-1)(a^2+a+1)
4)a^4-21a^2-100
=(a^2-25)(a^2+4)
=(a+5)(a-5)(a^2+4)
5)a^3-5a^2b-300ab^2
=a(a^2- 5ab-300b^2)
=a(a-20b)(a+15b)
6)(x^2+2)^2-9x^2
= (x^2+2+3x)(x^2+2-3x)
= (x+1)(x+2)(x^2+2-3x)
7)20x^2-39x+18
=(4x-3)(5x-6)
8)25x^2y^2-40xy+16
=(5xy-4)^2
9)a^2-4ab-12b^2
=(a-6b)(a+2b)
10)x^4+2x^2-3
=(x^2-1)(x^2+3)
=(x-1)(x+1)(x^2+3)
11)3x^2-11x+10
=(3x-5)(x-2)
12)6x^2-11x-10
=(3x+2)(2x-5)
13)x^2-5x+6
=(x-2)(x-3)