1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
maxonik [38]
3 years ago
8

How you do multiply complex numbers ? Example : (9 - 4i) (8 + 6i)

Mathematics
1 answer:
Andrew [12]3 years ago
6 0

You multiply them just as you would multiply any normal polynomials, except there is a special rule. Since we know that i = √-1, the rule is that i² = -1. So, let's multiply:

(9-4i)(8+6i) = 72+54i-32i-24i^2

Let's simplify this:

72+22i+(-24*-1)

72+22i+24 = 96+22i

Therefore, your answer is 96 + 22i.

You might be interested in
For questions 3 - 5, answer the questions about the equations.
mrs_skeptik [129]

Answer:

  infinite solutions

Step-by-step explanation:

Eliminate parentheses and collect terms:

  3x -12 +5 -x = 2x -7

  2x -7 = 2x -7

This is true for any value of x. There are an infinite number of solutions.

6 0
3 years ago
Dawn has been using two bank accounts to save money for a car. the difference between account 1 and account 2 is $100. if she us
asambeis [7]
1) name the variables:

 - amount in account 1 "a"
 - amount in account 2 "b"

2) trtanslate the statements into equations:

<span>- the difference between account 1 and account 2 is $100.

=> a - b = 100

-  if she uses 3/8 of account 1 and 7/8 of account 2, Dawn will have a down payment of $2,000.

=> (3/8)a + (7/8)b = 2000

3) solve the system of equations

(1) a - b = 100
(2) (3/8)a + (7/8b) = 2000

Steps:

- multiply equation (1) by 7 and equaton (2) by 8

=>

(1) 7a - 7b = 700
(2) 3a + 7b = 16,000

- add the two equations

=>

7a + 3a - 7b + 7b = 700 + 16,000

- combine like terms:

10a = 16,700

- divide by 10:

a = 16,700 / 10 = 1670

- use equation (1) to find b:

a - b = 100 => b = a - 100 = 1670 - 100 = 1570

Answer: Dawn has $ 1670 in account 1 and $ 1570 in account 2. </span>
8 0
3 years ago
Read 2 more answers
A rope which is 10.3 centimeters long is cut into 4 pieces of equal length. Write an equation to find the length of
alexdok [17]

Answer: x = 10.3 ÷ 4

Step-by-step explanation: if we were to work this out forgetting about the equation it can be worked out by dividing the 10.3 by 4 to find the length of the pieces so, now to express it as an equation, we have to add x into our sum 4 × ? = 10.3 : 4x = 10.3. The answer for x would be x = 2.58.

3 0
3 years ago
Read 2 more answers
31 POINTS!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Tresset [83]

Answer:

5 min

Hungarian 3.6 min

Polish nearly 1.4 min

270/190=1.4

5-1.4=3.6 min

3 0
3 years ago
How many fluid ounces are in a gallon?
alexgriva [62]

Answer:

128 fluid ounces

Step-by-step explanation:

5 0
3 years ago
Other questions:
  • the cafeteria at Midtown Middle School surveyed 575 students about their favorite food to find the number of students that respo
    7·1 answer
  • What is the midpoint of QR. Q(2,4) and R(-3,9)
    13·1 answer
  • The function h is defined by h(y) = 2y - 7<br> VWhat is the value of h (8) ?<br> АВАА
    12·1 answer
  • Stocks A and B have the following probability distributions of expected future returns: Probability A B 0.1 (12%) (38%) 0.2 6 0
    14·1 answer
  • (4,4) and (-2,-2) round to the nearest tenth
    7·1 answer
  • Which number is larger? Justify your answer -4.03 or -4.3
    11·1 answer
  • 100 POINTS!!!! I anwered A and B i just need help with C
    13·1 answer
  • Answer helppppp plsss i’m on quizzzz
    9·1 answer
  • If Luis can type 168 words in 4 minutes, what is his speed per minute?
    15·2 answers
  • How long is ⅓ of one hour?
    6·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!