Select the correct answer.

Which complex number is equivalent to the given expression?

(2 + i)(8 - 3i) - (23 + 34i)

A. -10 + 48i
B. -10 - 20i
C. -4 - 32i
D. -13 - 361



Answer :

To find the complex number equivalent to the expression [tex]\((2 + i)(8 - 3i) - (23 + 34i)\)[/tex], we can tackle the problem step-by-step:

1. First, multiply the complex numbers [tex]\((2 + i)(8 - 3i)\)[/tex]:

- Use the distributive property (also known as the FOIL method for binomials):

[tex]\[ (2 + i)(8 - 3i) = 2 \cdot 8 + 2 \cdot (-3i) + i \cdot 8 + i \cdot (-3i) \][/tex]

- Perform the multiplications:

[tex]\[ 2 \cdot 8 = 16 \][/tex]
[tex]\[ 2 \cdot (-3i) = -6i \][/tex]
[tex]\[ i \cdot 8 = 8i \][/tex]
[tex]\[ i \cdot (-3i) = -3i^2 \][/tex]

- Remember that [tex]\(i^2 = -1\)[/tex], so:

[tex]\[ -3i^2 = -3(-1) = 3 \][/tex]

- Combine all the terms:

[tex]\[ 16 - 6i + 8i + 3 \][/tex]

- Simplify this to:

[tex]\[ 19 + 2i \][/tex]

2. Next, subtract the complex number [tex]\((23 + 34i)\)[/tex] from the result:

- Subtract the real parts:

[tex]\[ 19 - 23 = -4 \][/tex]

- Subtract the imaginary parts:

[tex]\[ 2i - 34i = -32i \][/tex]

3. Combine the results:

- The result is:

[tex]\[ -4 - 32i \][/tex]

Thus, the complex number equivalent to the given expression [tex]\((2 + i)(8 - 3i) - (23 + 34i)\)[/tex] is [tex]\(-4 - 32i\)[/tex].

So the correct answer is:

C. [tex]\(-4 - 32i\)[/tex]