Question

For the equation 2x^3 -11x^2 + 12x + 9 = 0 , the root of 3 has a multiplicity of

A. 1
B. 2
C. 3

And please explain why ! (I have a hunch it’s 2 but I don’t know how to explain it)

Answer 1

Answer: 2

Reason:

2x^3 - 11x^2 + 12x + 9

= 2x^2(x-3) - 5x(x-3) -3(x-3)

= (x-3)(2x^2 - 5x - 3)

= (x-3)^2 (2x + 1)