8 is a common factor for all coeficients so we factor it out first: 8(2x^2 + x + 4). Now we have to check can we factor the quadratic equasion in the brackets to linear factors. To do that we need to check is the discriminant D=b^2 - 4ac > 0 where a=2, b=1 and c=4. When we insert our numbers, we get: D= -31. We see that D < 0 so 8(2x^2 + x + 4) is the completely factored form.
