let f(x) = 3x^3-9x^2-31x+5
f(1) = 3 - 9 - 31 + 5 ≠ 0
f(-1) ≠ 0
f(5) = 375 - 225 - 155 + 5 = 0
so x = 5 , and x-5 is a factor
I assume you know how to perform synthetic division.
You should get (x-5)(3x^2 + 6x - 1)
This quadratic produces two more zeros, use the quadratic formula to find them
3x^3-9x^2-31x+5=0
How do I find the zeros, using synthetic division
2 answers
There is a nice online calculator at
https://www.mathportal.org/calculators/polynomials-solvers/synthetic-division-calculator.php
It will show the steps involved.
https://www.mathportal.org/calculators/polynomials-solvers/synthetic-division-calculator.php
It will show the steps involved.