Find all the zeros of the equation
-2x^4+27x^2+1200=0

For this case we have the following polynomial:
 
 To solve the problem we apply the following steps:
 1) We make a change of variables u = x ^ 2
 2) We rewrite the polynomial
 3) Solve the quadratic equation using the formula for the quadratic equation
 4) We return the change and find four roots
 
 See attached image for procedure and solution

The answer to your question is b