Question

I️ need help what’s on the picture

Answer 1

$\bf \sqrt{-100}\implies \sqrt{-1\cdot 100}\implies \sqrt{-1}\cdot \sqrt{100}\implies \sqrt{-1}\cdot \sqrt{10^2} \\\\\\ i\cdot 10\implies 10i\implies \stackrel{a}{0}+\stackrel{bi}{10i}$

Answer 2

I think this is what it means 

divide, to separate into equal parts by the process of mathematical division;which helps it , apply the mathematical process of division to: Eight divided by four is two.