If you know that 3+sqrt 11 is a root of a polynomial function, then the name given to 3 -sqrt 11, another root of that same function, is ?

Radical conjugate.

Step-by-step explanation:

By definition   and are called "Conjugate radicals".

Therefore, by this definition, you can know the following:

1) is the conjugate of

2) is the conjugate of .

Then, since you know that is a root of a polynomial function, therefore you can conclude that the name given to the other root of the same function is the following:

"Radical conjugate".

it's equivalent, so we can say that its equal.

let's call the denominator x and the numerador is 18 less then denominator, x - 18.

multiply

2.x = 5.(x - 18)

2x = 5x - 90

90 = 5x - 2x

90 = 3x

x = 90/3

x = 30

so: