Question

Which of the following represents the zeros of f(x)=3x^3-10x^2-81x 28? Answer choices: A.) 7, -4,1/3 B.) 7,-4, -1/3 C.) 7,4,1/3 D.) 7,4,-1/3

Answer 1

The right function is f(x)=3x^3-10x^2-81x + 28

You can realize that 7 is a root because it is in all the answers.

So you can divide the polynomial by x - 7. If you do it you can find that the quotient is 3x^2 + 11x - 4

Now you can use the quadratic formula to find the other two roots.

If you do it, you will find they are x = 1/3 and x = -4.

So the answer is option A) 7, -4, 1/3

And the polynomial can be written as (x - 7)(x + 4) (x -1/3)