Find the sum of (-4 + i) and (10 - 5i).

a. - 3 + 5i

b. - 3 - 5i

c. 6 - 4i

d. 6 - 6i

To add complex numbers, it is necessary to group the similar terms (real and real, then imaginary and imaginary) before simplifying. This will be done as follows:

(-4 + i) + (10 - 5i)

Grouping similar terms:

(-4 + 10) + (i - 5i)

6 - 4i

From the choices, the correct answer is C.