question\nsimplify the expression to ( a + bi ) form:\n( sqrt{4}-sqrt{-81}+sqrt{4}+sqrt{-36} )

question\nsimplify the expression to ( a + bi ) form:\n( sqrt{4}-sqrt{-81}+sqrt{4}+sqrt{-36} )

question\nsimplify the expression to ( a + bi ) form:\n( sqrt{4}-sqrt{-81}+sqrt{4}+sqrt{-36} )

Answer

Explanation:

Step1: Simplify square roots

$$ \begin{align*} \sqrt{4}& = 2\ \sqrt{-81}&=\sqrt{81\times(- 1)} = 9i\ \sqrt{4}& = 2\ \sqrt{-36}&=\sqrt{36\times(-1)}=6i \end{align*} $$

Step2: Substitute into the expression

Substitute the simplified values into the original expression (\sqrt{4}-\sqrt{-81}+\sqrt{4}+\sqrt{-36}), we get (2 - 9i+2 + 6i)

Step3: Combine like - terms

Combine the real parts (2 + 2=4) and the imaginary parts (-9i+6i=-3i)

Answer:

(4-3i)