The correct answers are: 1/2, 2 and -2.
To get this, factor f(x)
f(x)=2x^3-x^2-8x+4
f(x)= (2x^3-x^2) - (8x -4)
f(x)= (2x-1)(x^2) + (2x-1)(-4)
f(x)= (2x-1)(x^2-4)
f(x)= (2x-1)(x-2)(x+2)
2x-1=0
2x=1
x=1/2
x-2=0
x=2
x+2=0
x=-2
Since you have to distribute both numbers, you'll end up with x^2-3x+4x-12 then simplify and it is x^2+x-12
The measure of angle 3 is 150 degrees
