Question

given f(x) = x^3 + 5x^2 - 4X - 20
use synthetic division to find f(3)
how do I do it????

Answer 1

then it says " find all zeros of f(x) algebraically."

Answer 2

why does the 3 become -3? o.O

Answer 3

3| 1 5 -4 -20
3 24 60
__________________
1 8 20| 40 <----- answer

Answer 4

sorry, i misread it as division

Answer 5

it's alright.
do you know how to do the second part?

Answer 6

find the Possible Rational Zeroes, LUB and GLB and test the 0s with synthetic division