Answer:
4 possible real zeroes
solutions are

x = 1
x = -1
Explanation:
4th order polynomial therefore there are 4 possible solutions.
factoring it:
(x^2-3)(x^2-1)
Solve for x
x^2 - 3 = 0
x^2 = 3 ; take the square root of both sides

x^2 - 1 = 0
x^2 = 1
x = 1
x = -1