Question

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

x = 1/3
x = 3 1/3
x = 6 1/3
x = 9 1/3

Answer 1

C. 19/3 is equivalent to 6 1/3.

Answer 2

one zero of the quadratic function is x = 6 1/3

Third option is correct.

Step-by-step explanation:

The given quadratic function is
`f(x)=9x^2-54x-19`

For the zeros of this quadratic function, we have f(x)=0

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

We can write the middle terms as: -54x = 3x-57x

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

Take GCF as shown below

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

Factored out the common term

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

Apply Zero product property

`3x+1=0,3x-19=0`

Solve for x

`3x=-(1)/(3),(19)/(3)`

We can write 19/3 as 6 1/3.

Hence, one zero of the quadratic function is x = 6 1/3

Third option is correct.