SaiBook.us Algebra

Home Course Section

Schedule Admission Social

Lesson Example Discussion Quiz: Class Homework

Step-4

Title: Addition and Subtraction of complex numbers

Grade: 8-b Lesson: S2-L5

Explanation: Hello Students, time to practice and review the steps for the problem.

Lesson Steps

Discussion: Step1 Step2 Step3 Step4 Step5

Step	Type	Explanation	Answer
1	Problem	Add three complex numbers (17 + 3i) + (9 + 4i) + ( 2.5i - 12).
2	Step	The given complex numbers are	(17 + 3i) + (9 + 4i) + ( 2.5i - 12)
3	Hint	Separate the real and imaginary parts:	(17 + 9 - 12) + (3i + 4i + 2.5i)
4	Step	Combine the real parts and then simplify it:	17 + 9 -12 = 14
5	Step	Combine the imaginary parts and then simplify it:	3i + 4i + 2.5i = 9.5i
6	Hint	Combine the real part and imaginary part:	14 + 9.5i
7	Step	So, the addition of complex number is 14 + 9.5i.
8	Choice.A	Option A (14i + 9.5) is incorrect because it incorrectly orders the real and imaginary parts and the real part should be 14, not 9.5	14i + 9.5
9	Choice.B	14 - 9.5i is incorrect because it incorrectly subtracts 9.5i instead of adding it. The correct imaginary part should be + 9.5i, not - 9.5i	14 - 9.5i
10	Choice.C	It incorrectly combines the real and imaginary parts. The real part should be 14, not -9.5. The imaginary part should be 9.5i, not 14i	14i - 9.5
11	Choice.D	The addition of complex numbers has been done accurately. So, it is correct	14 + 9.5i
12	Answer	Option	D
13	Sumup	Can you summarize what you’ve understood in the above steps?

Step

Type

Explanation

Answer

Problem

Add three complex numbers (17 + 3i) + (9 + 4i) + ( 2.5i - 12).

Step

The given complex numbers are

(17 + 3i) + (9 + 4i) + ( 2.5i - 12)

Hint

Separate the real and imaginary parts:

(17 + 9 - 12) + (3i + 4i + 2.5i)

Step

Combine the real parts and then simplify it:

17 + 9 -12 = 14

Step

Combine the imaginary parts and then simplify it:

3i + 4i + 2.5i = 9.5i

Hint

Combine the real part and imaginary part:

14 + 9.5i

Step

So, the addition of complex number is 14 + 9.5i.

Choice.A

Option A (14i + 9.5) is incorrect because it incorrectly orders the real and imaginary parts and the real part should be 14, not 9.5

14i + 9.5

Choice.B

14 - 9.5i is incorrect because it incorrectly subtracts 9.5i instead of adding it. The correct imaginary part should be + 9.5i, not - 9.5i

14 - 9.5i

Choice.C

It incorrectly combines the real and imaginary parts. The real part should be 14, not -9.5. The imaginary part should be 9.5i, not 14i

14i - 9.5

Choice.D

The addition of complex numbers has been done accurately. So, it is correct

14 + 9.5i

Answer

Option

Sumup

Can you summarize what you’ve understood in the above steps?

Discussion: Step1 Step2 Step3 Step4 Step5