Question

Find all rational roots of the equation

x^5-9x^4-10x^3+90x^2+9x-81=0

Answer 1

\[x^5-9x^4-10x^3+90x^2+9x-81=0\]

Answer 2

+/- 1
+/- 3
+/- 9
+/- 27
+/- 81

Ten to try. Go!

Answer 3

First I start with a bit of trial and error. If you sub x = 1 into the equation, it turns to 0. so you know x = 1 is a root and x - 1 = 0