How do you factor 4y=x^3-4x^2-11x+30 ?
1 Answer
Sep 2, 2016
Explanation:
By the rational roots theorem, any rational zeros of
That means that the only possible rational zeros are:
+-1, +-2, +-3, +-5, +-6, +-10, +-15, +-30
If
x^3-4x^2-11x+30 = (8)-4(4)-11(2)+30 = 8-16-22+30 = 0
So
x^3-4x^2-11x+30 = (x-2)(x^2-2x-15)
To factor the remaining quadratic, find a pair of numbers with difference
x^2-2x-15 = (x-5)(x+3)
Putting it all together, we have:
4y = (x-2)(x-5)(x+3)