Question

question 1 of 5
select the correct answer.
what is the value of this expression?
(10 - 4i)(4 - 5i) + (-15 + 20i)
5 + 46i
55 + 54i
55 - 54i
5 - 46i

Explanation:

Step1: Multiply the complex numbers

First, we multiply \((10 - 4i)(4 - 5i)\) using the distributive property (FOIL method).

$$
LATEXBLOCK0
$$

Since \(i^{2}=- 1\), we substitute that in:

$$
LATEXBLOCK1
$$

Step2: Add the remaining complex number

Now we add \((-15 + 20i)\) to the result from Step 1:

$$
LATEXBLOCK2
$$

Answer:

\(5 - 46i\) (the option: 5 − 46i)