Question

$9 - \sqrt{ - 64}$write the equation as a complex number

Answer 1

$A)9-8i$

Explanation

$9-\sqrt[]{-64}$

Step 1

Let's remember that

A complex number is an object of the form

$a+bi$

where a and b are real numbers and

$\begin{gathered} i^2=-1 \\ i=\sqrt[]{-1} \end{gathered}$

so

$\begin{gathered} 9-\sqrt[]{-64} \\ 9-\sqrt[]{-1\cdot64} \\ 9-\sqrt[]{-1}\sqrt[]{64} \\ 9-8\sqrt[]{-1} \\ 9-8i \end{gathered}$

therefore, the answer is

$A)9-8i$

I hope this helps you