a,6x^2-11x+3
=6x^2-2x-9x+3
=(6x^2-2x)-(9x-3)
=2x(3x-1)-3(3x-1)
=(2x-3)(3x-1)
d,4x^4-1
=(2x^2)^2-1^2
=(2x^2-1)(2x^2+1)
l,x^7 + x^5 + 1
=x^7-x^6+x^5-x^3+x^2+x^6-x^5+x^4-x^2+x+x^5-x^4+x^3-x+1
=(x^2+x+1)(x^5-x^4+x^3-x+1)
g,x^8+x^4+1
=(x^8+2x^4+1)-x^4=(x^4+1)^2-x^4
=(x^4-x^2+1)(x^4+x^2+1)
=(x^4-x^2+1)[(x^4+2x^2+1)-x^2]
=(x^4-x^2+1)[(x^2+1)^2)-x^2]