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
tigry1 [53]
3 years ago
14

Multiply the following complex numbers (7 + 2i)(2+3i) O A. 20-25i B. 8-25i O C. 8+ 25i O D. 20-25i​

Mathematics
1 answer:
ruslelena [56]3 years ago
5 0

Đáp án là C: 8+25i nhé

8+ 25i

You might be interested in
The LB Company has long manufactured a light bulb with an average life of 5400 hours. Company researchers have recently develope
elena55 [62]
<h2><u>Answer with explanation</u>:</h2>

Let \mu be the average life of light bulbs.

As per given , we have

Null hypothesis : H_0 : \mu =5400

Alternative hypothesis : H_a : \mu >5400

Since H_a is right-tailed and population standard deviation is also known, so we perform right-tailed z-test.

Formula for Test statistic : z=\dfrac{\overlien{x}-\mu}{\dfrac{\sigma}{\sqrt{n}}}

where, n= sample size

\overline{x}= sample mean

\mu= Population mean

\sigma=population standard deviation

For n=95,\ \overline{x}=5483\ \&\ \sigma=500, we have

z=\dfrac{5483-5400}{\dfrac{500}{\sqrt{95}}}=1.61796786124\approx1.6180

Using z-value table , Critical one-tailed test value for 0.06 significance level :

z_{0.06}=1.5548

 Decision : Since critical z value (1.5548) < test statistic (1.6180), so we reject the null hypothesis .

[We reject the null hypothesis when critical value is less than the test statistic value .]

Conclusion : We have enough evidence at 0.06 significance level to support the claim that the new filament yields a longer bulb life

8 0
4 years ago
How to factor 25x^2 - 81= 0
dalvyx [7]
Your question is a difference of squares. both terms that need to be factored are squared. to solve take the square root of each put into two terms one of addition and one of subtraction.

anwser= (5x-9)(5x+9)

the reason this works is because when you foil you get
25x²-45x+45x-81 
the middle terms cancel revealing
25x²-81
4 0
3 years ago
-7 2/3 + ( -5 1/2 ) + 8 3/4 = ? <br><br> A: -4 5/12 <br> B: -21 11/12 <br> C: -4 2/3 <br> D: 6 7/12
frez [133]

Answer:

-4 5\12

Step-by-step explanation:

Identify the Least Common Denominator, 12, then just simply evaluate.

8 0
3 years ago
Define the following in your own words. Please do not copy and paste of the internet. Thank you in advance
bulgar [2K]

Answer:

Perpendicular bisector - A line that bisects another line into two equal halves so that four right angles are created.

Cylinder - A 3D solid with circles as its bases.

Plane - A flat, 2D surface that extends infinitely.  

Regular Polygon -  A polygon where all angles and all sides are equal  (ex. square, pentagon, triangle).

3 0
3 years ago
--2m + 4n2 for m = -6 and n=-5<br> Evaluate the expression
Tamiku [17]

Answer: 112

Step-by-step explanation:

Since we were given m and n, we plug them into the expression and solve.

-2(-6)+4(-5)²            [exponent]

-2(-6)+4(25)            [multiply]

12+100                     [add]

112

Now, we know that the value of the expression is 112.

7 0
3 years ago
Other questions:
  • Your credit limit is $2,500 what is the max you should ever owe on this card?
    14·1 answer
  • Use a number line to name two numbers that are the same distance apart as 3.2 and 3.8
    14·1 answer
  • the value of a new automobile depreciates 15% during the first year, and 16% during the second year. What is its depreciated val
    6·1 answer
  • HELP! Anyone! PLEASE?!!!!!
    5·1 answer
  • Jin has pounds of birdseed. If he uses 1/8 pound a
    7·1 answer
  • HELP IMMEDIATELY!!
    9·2 answers
  • Imagine that you are plotting points on a coordinate plane. Each axis is labeled with integers from −5 to 5. Explain how you wou
    10·1 answer
  • Can someone please help?
    14·2 answers
  • The movie rental store CineStar offers customers two choices. Customers
    10·1 answer
  • Solve for X<br> 50 points in it for you plus a thanks, 5 star rating and brainliest!
    6·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!