F(x) = 5x4 – 8x3 + 41x2 – 72x – 36

Rational root theorem

-72x+42

Step-by-step explanation:

5x4 – 8x3 + 41x2 – 72x – 36

20-24+82-72x-36

-72x+42

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:

answer is the third choice:

3x^5+4x^4+x^3+2x^2-10x-7=0

step-by-step explanation: