i need help figuring out this question

Answer:
nre, nre
Step-by-step explanation:
Given
[tex]4b^2 + 16 = 0[/tex]
Required
Solve
[tex]4b^2 + 16 = 0[/tex]
Subtract 16 from both sides
[tex]4b^2 +16 -16 = 0 - 16[/tex]
[tex]4b^2 = - 16[/tex]
Divide both sides by 4
[tex]b^2 = -4[/tex]
Take square roots of both sides
[tex]b = \sqrt{-4[/tex]
[tex]\sqrt{-4} \to[/tex] Complex number
Hence, no real root exist