Question

Select the correct answer.
Write (21 − 4i) − (16 + 7i) + 28i as a complex number in standard form.

A.
5 + 39i
B.
5 + 17i
C.
5 − 39i
D.
5 − 17i

Answer 1

Answer:

B) 5 + 17i is your answer.

Step-by-step explanation:

In order to write this equation as a complex number in standard form, you must first simplify each term.

Apple the distributive property.

21 - 4i - 1 * 16 - (7i) + 28i

Multiply -1 by 16.

21 - 4i -16 - (7i) + 28i

Multiply 7 by -1.

21 - 4i - 16 - 7i + 28i

Now simplify by adding terms :)

Subtract 16 from 21.

5 - 4i - 7i + 28i

Subtract 7i from -4i.

5 - 11i + 28i

Add -11i and 28i.

= 5 + 17i