Question

Which is a zero of the quadratic function f(x) = 9x2 – 54x – 19?

x =
x = 3
x = 6
x = 9

Answer 1

C

Explanation:

Answer 2

Let us find Zeros of our equation by equating our quadratic function to zero.

`9x^(2)-54x-19=0`

We will factor out our quadratic function by splitting the middle term.

`9x^(2)-57x+3x-19=0`

Now we will factor out GCF from both groups. We can see that GCF of our first group is 3 and GCF of second group is 1.

`3x(3x-19)+1(3x-19)=0`

After factoring out the common binomial we will get,

`(3x-19)(3x+1)=0`

Now we will equate each binomial to zero to find both zeros of our quadratic function.

`3x-19=0 \text{ or }3x+1=0`

`3x=19 \text{ or } 3x=-1`

`x=(19)/(3)=6(1)/(3)\text{ or } x=(-1)/(3)`

Therefore,
`x=6(1)/(3)` and
`x=(-1)/(3)` are zeros of our given quadratic function.