Answer
-2, -1, 1, and 2 of multiplicity one
See graph below.
Work Step by Step
The question asks for all real zeros of P(x), their respective multiplicities, and the graph of P(x)
Given $P(x) = x^4 - 5x^2 + 4$
$P(x) = (x^2 - 4) (x^2 - 1)$
$P(x) = (x-2)(x+2)(x-1)(x+1)$
Set $P(x) = 0$
Thus x = -2, -1, 1, 2
To determine multiplicity, it is the power of the root determined from setting P(x) = 0
So -2, -1, 1, and 2 of multiplicity one
See graph below.