What is the sum of [tex]\(12 - 5i\)[/tex] and [tex]\(-3 + 4i\)[/tex]?

A. [tex]\( -16 + 63i \)[/tex]
B. [tex]\( 9 - i \)[/tex]
C. [tex]\( 9 - 9i \)[/tex]
D. [tex]\( 15 - 9i \)[/tex]



Answer :

To find the sum of the complex numbers [tex]\(12 - 5i\)[/tex] and [tex]\(-3 + 4i\)[/tex], we will add their real parts and their imaginary parts separately.

1. Identify the complex numbers:

[tex]\[ z_1 = 12 - 5i \][/tex]
[tex]\[ z_2 = -3 + 4i \][/tex]

2. Add the real parts:

The real part of [tex]\(z_1\)[/tex] is 12.
The real part of [tex]\(z_2\)[/tex] is -3.

[tex]\[ \text{Real part: } 12 + (-3) = 9 \][/tex]

3. Add the imaginary parts:

The imaginary part of [tex]\(z_1\)[/tex] is -5i.
The imaginary part of [tex]\(z_2\)[/tex] is 4i.

[tex]\[ \text{Imaginary part: } -5i + 4i = -1i \text{ or } -i \][/tex]

4. Combine the results:

[tex]\[ (12 - 5i) + (-3 + 4i) = 9 - i \][/tex]

So, the sum of [tex]\(12 - 5i\)[/tex] and [tex]\(-3 + 4i\)[/tex] is [tex]\(9 - i\)[/tex].

Now, let's compare this result with the given options.

- [tex]\(-16 + 63i\)[/tex]
- [tex]\(9 - i\)[/tex]
- [tex]\(9 - 9i\)[/tex]
- [tex]\(15 - 9i\)[/tex]

The correct answer is [tex]\(9 - i\)[/tex].