Question

complete the steps to solve the polynomial equation x3-21x=-20 according to the rational root theorem, which number is a potential root of the polynomial?

Answer 1

x^3 - 21x + 20 = 0

potential roots are factors of 20 eg 1, 2 ,4 ,5, 10, 20 and the negative values of these
1 looks like a rots . Try it:-
f(1) = 1 - 21 + 20 = -20+20 = 0

Yes 1 is a solution.

2 is not.

Try 4:-

4^3 - 21*4 + 20 = 64 - 84 + 20 = 0

Try 5 No
Try 10 - N0
20 no.

Try -4 - No
-5:-

Yes

Roots are 1, 4 and -5

Answer 2

in Quizlet: 1st question is 1 2nd question is 1,4,-5

Explanation: