identify the number of zeros ....thank you

Question

2x^4-250x=0

Answer 1

ALL polynomials of degree n have exactly n zeroes.
The Fundamental Theorem of Algebra
However, not all may be real. In this case,
2x^4 - 250x
= 2x(x^3-125) = 2x(x^3 - 5^3)
= 2x(x-5)(x^2+5x+25)
So, there are two real roots and two complex roots