a) 6x^2-11x+3 = 6x^2-2x-9x+3 = 2x(3x-1)-3(3x-1) = (2x-3)(3x-1)
b) 2x^2+3x-27 = 2x^2+9x-6x-27 = x(2x+9)-3(2x+9) = (x-3)(2x+9)
c) 8x^2+10x-3 = 8x^2+12x-2x-3 = 4x(2x+3)-(2x+3) = (4x-1)(2x+3)
d) 8x^2-2x-1 = 8x^2+2x-4x-1 = 2x(4x+1)-(4x+1) = (2x-1)(4x+1)
e) x^5+x-1 = x^5-x^4+x^4+x^3-x^3+x^2-x^2+x-1 = (x^5-x^4+x^3)+(x^4-x^3+x^2)-(x^2-x+1)
= x^3(x^2-x+1)+x^2(x^2-x+1)-(x^2-x+1) = (x^3+x^2-1)(x^2-x+1)