A student multiplies (4+5i) (3-2i) incorrectly and obtains 12-10i. What is the student's mistake? Select the two correct answers. A. They multiplied the second number by the real part of the first number. B. In the multiplication of the imaginary parts, the student forgot to square the i. C. The student has only multiplied the real parts and the imaginary parts. D. The student has added the real parts and multiplied the imaginary parts. E. The student has multiplied the second number by the imaginary part of the first number.

Answers

Answer 1

Answer:

B. In the multiplication of the imaginary parts, the student forgot to square the i. C. The student has only multiplied the real parts and the imaginary parts.

Step-by-step explanation:

Before we figure out the student mistake, let us find the product of the complex numbers ourselves first.

(4+5i) (3-2i)

open the parenthesis

= 4(3)-4(2i)+3(5i)+5i(-2i)

= 12-8i+15i-10i²

Note that in complex number, i² = -1, hence the expression will become;

= 12-8i+15i-10(-1)

= 12-8i+15i+10

collect like terms by separating the real from imaginary part

= 12+10-8i+15i

= 22+7i

From the students answer i.e 12-10i, it can be concluded that;

In the multiplication of the imaginary parts, the student forgot to square the i and the student has only multiplied the real parts and the imaginary parts 4 and 3 to get 12


Related Questions

What is the slope of the line that passes through the points (-6, 8) and (−16,33)? Write your answer in simplest form.

Answers

Answer:

[tex]-\frac{5}{2}[/tex]

Step-by-step explanation:

[tex]\frac{change in Y}{change in X}[/tex]

plug in points:

[tex]\frac{8-33}{-6+16}[/tex]

[tex]\frac{-25}{10}[/tex]

Simplify:

[tex]-\frac{5}{2}[/tex]

what is the value of the expression below when y=5? y^2-3y+6

Answers

Plug in 5 for y
5^2-3(5)+6
1) evaluate the power: 25-3(5)+6
2) multiply: 25-15+6
3) add and subtract: 10+6 =16

Answer: 16

Answer:

y = 5

y^2 - 3y + 6

= 5^2 - 3(5) + 6

= 25 - 15 + 6

= 10 + 6

= 16

I will give the brainiest

Tim has 74 socks, all in pairs. He has 1 more pair of white socks than black socks. How many
individual socks of each color does he have?

black socks

white socks

Answers

Answers:

36 individual black socks

38 individual white socks

Check: 36+38 = 74 total individual socks

====================================================

Work Shown:

b = number of pairs of black socks

w = number of pairs of white socks

w = b+1 since he has 1 more pair of white socks compared to black socks

2b = number of individual black socks

2w = number of individual white socks

2b+2w = total number of individual socks

2b+2w = 74

2b+2(b+1) = 74 .... plug in w = b+1

2b+2b+2 = 74 ... distribute

4b+2 = 74

4b = 74-2 .... subtracting 2 from both sides

4b = 72

b = 72/4 ... dividing both sides by 4

b = 18 is the number of pairs of black socks he has

2b = 2*18 = 36 is the number of individual black socks he has

w = b+1 = 18+1 = 19 is the number of pairs of white socks he has

2w = 2*19 = 38 is the number of individual white socks he has

2b+2w = 36+38 = 74 individual socks overall

Which of the following employees has the greatest total employee compensation? a. Employee A: total job benefits $68,100 and total job expenses $100 b. Employee B: total job benefits $68,400 and total job expenses $300 c. Employee C: total job benefits $68,700 and total job expenses $800 d. Employee D: total job benefits $69,000 and total job expenses $1,000

Answers

Answer:

B is the correct answer

Step-by-step explanation:

Answer:

Which of the following employees has the greatest total employee compensation?

a. ))   Employee A: total job benefits $68,100 and total job expenses $100

b. ))   Employee B: total job benefits $68,400 and total job expenses $300  {{{   CORRECT  }}}

c. ))   Employee C: total job benefits $68,700 and total job expenses $800

d. ))   Employee D: total job benefits $69,000 and total job expenses $1,000

Step-by-step explanation:

Edge 2021

can someone pleaseee help me

Answers

The reciprocal of -4/13 is -13/4

Answer

13/4

Step-by-step explanation:

Solve for the specified variable.
(c+d)
Solve Q=
for d.
2

Answers

Answer:

2Q -c = d

Step-by-step explanation:

Q= ( c+d)/2

Multiply each side by 2

2Q = ( c+d)/2 *2

2Q = ( c+d)

Subtract c from each side

2Q - c = c+d-c

2Q -c = d

Steps to solve:

Q = (c+d)/2

~Simplify

Q = 1/2c + 1/2d

~Subtract 1/2c to both sides

Q - 1/2c = 1/2d

~Divide 1/2 to both sides

d = 2q - c

Best of Luck!

A genetic test is used to determine if people have a predisposition for thrombosis, which is the formation of a blood clot inside a blood vessel that obstructs the flow of blood through the circulatory system. It is believed that 3% of people actually have this predisposition. The genetic test is 98% accurate if a person actually has the predisposition, meaning that the probability of a positive test result when a person actually has the predisposition is 0.98. The test is 97% accurate if a person does not have the predisposition. What is the probability that a randomly selected person who tests positive for the predisposition by the test actually has the predisposition? (Round your answer to four decimal places.)

Answers

Idk mane but uh I just don’t know

The perimeter of a certain rectangle is 16 times the width. The length is 12cm more than the width. Find the length of the rectangle. Show work.

Answers

Answer:

Step-by-step explanation:

width = w

length = 12 + w

 

Perimeter of rectangle = 2*length + 2*width since perimeter measures the distance around an object.

 

The perimeter of a certain rectangle is 16 times the width means 2 * (12 + w) + 2 *w = 16w

24 + 2w + 2w = 16w

24 + 4w = 16w  subtract 4w from both sides

24 = 12 w  divide both sides by 12

2 = w

 

width = 2 cm

length = 12 + 2 = 14 cm

In the quadrilateral,all the sides are equal,but diagonals are not equal is called?

Answers

Answer:

I think it would be a rhombus.

The rectangle below has an area of x^2+11x+28x 2 +11x+28x, squared, plus, 11, x, plus, 28 square meters and a length of x+7x+7x, plus, 7 meters. What expression represents the width of the rectangle?

Answers

Answer:

[tex]Width = x + 4[/tex]

Step-by-step explanation:

Given

Shape: Rectangle

[tex]Area = x^2 + 11x + 28[/tex]

[tex]Length = x + 7[/tex]

Required

Determine the width

For a rectangle:

[tex]Area = Length * Width[/tex]

Substitute values for Length and Area

[tex]x^2 + 11x + 28 = (x + 7) * Width[/tex]

Factorize the expression on the left hand side

[tex]x^2 + 7x + 4x + 28 = (x + 7) * Width[/tex]

[tex]x(x + 7) + 4(x + 7) = (x + 7) * Width[/tex]

[tex](x + 7)(x + 4) = (x + 7) * Width[/tex]

Divide both sides by x + 7

[tex]Width = x + 4[/tex]

A copy machine makes 112 copies in minutes3 and30 seconds. How many copies does it make per minute?

Answers

Answer:

32

Step-by-step explanation:

It takes a total of 210 seconds to make 112 copies.

Divide 210 by 60 to get 3.5

(If you divide 210 by 3.5 you get 60 sec.)

Next, divide 112 by 3.5

The copy machine makes 32 copies in one minute.

beginning of Tear Assessment Grade 8 Mathematics
37 OT 42
A rectangular prism and its dimensions are shown in the diagram.
6.5 in.
5 in.
7.5 in.
What is the total surface area of this prism in square inches?

Answers

Answer: 237.5 square inches

Step-by-step explanation:

Total surface area  of rectangular prism  = 2 (lw+wh +hl)

, where l= length

w = width

h= height

Given:  A rectangular prism and its dimensions are.

6.5 in.  ,5 in.  ,7.5 in.

Then, the total surface area of this prism  = 2 (6.5×5 + 6.5 × 7.5 + 5×7.5)

= 2 (32.5+ 48.75 + 37.5)

= 2 (118.75)

= 237.5

Hence, the total surface area of this prism = 237.5 square inches

Answer:

237.5

Step-by-step explanation:

took a test

What is 9+(5x10)+1-(15x2)

Answers

Answer:

30

Step-by-step explanation:

=9 + 5 x 10 + 1 + -15 x 2 = ( 5 x 10 ) + ( −15 x 2) + ( 9 +1  ) = 5 x 10 + −15 x 2 + 10

Answer:

30

Step-by-step explanation:

9+(5x10)+1-(15x2)

First, we must evaluate the numbers in the parentheses. (5x10) is 50, and (15x2) is 30. Since we have the answers to that, we can now put the expression as: 9 + (50) + 1 - (30).

9 + (50) = 59

59 + 1 = 60

60 - (30) = 30

Therefore, the answer is 30.

Hope this helped!

Simply 2p(p+2)-3p(2p-3) =

Answers

Answer:

p (13 - 4 p)

Step-by-step explanation:

Simplify the following:

2 p (p + 2) - 3 p (2 p - 3)

Hint: | Pull a common factor out of 2 p (p + 2) - 3 p (2 p - 3).

Factor p out of 2 p (p + 2) - 3 p (2 p - 3), resulting in p (2 (p + 2) - 3 (2 p - 3)):

p (2 (p + 2) - 3 (2 p - 3))

Hint: | Distribute 2 over p + 2.

2 (p + 2) = 2 p + 4:

p (2 p + 4 - 3 (2 p - 3))

Hint: | Distribute -3 over 2 p - 3.

-3 (2 p - 3) = 9 - 6 p:

p (2 p + 9 - 6 p + 4)

Hint: | Group like terms in 2 p - 6 p + 4 + 9.

Grouping like terms, 2 p - 6 p + 4 + 9 = (4 + 9) + (2 p - 6 p):

p (4 + 9) + (2 p - 6 p)

Hint: | Combine like terms in 2 p - 6 p.

2 p - 6 p = -4 p:

p (-4 p + (4 + 9))

Hint: | Evaluate 4 + 9.

4 + 9 = 13:

Answer: p (13 - 4 p)

what is the solution to this system of equations?
x-2y=15
2x + 4y=-18​

Answers

Answer:

x = 3; y = -6

Step-by-step explanation:

 x - 2y =  15

2x + 4y = -18​

Multiply both sides of the first equation by 2. Write the second equation below it, and add the two equations.

     2x - 4y = 30

(+)  2x + 4y = -18

---------------------------

     4x         = 12

4x/4 = 12/4

x = 3

Now we substitute 3 for x in the first equation and solve for y.

x - 2y = 15

3 - 2y = 15

-2y = 12

y = -6

Answer: x = 3; y = -6

the sum of three numbers is 116. The first number is 6 more than the third. The second number is 3 times the third. What are the numbers?NEED DONE ASAP

Answers

Answer:

107

Step-by-step explanation:

sum means addition so 3 + 6 = 9 116 - 9 = 107 hope it helps    <3

Si se reduce en 5 unidades de mil el número 23 657, ¿cuál número se obtiene? a) 23 607 b) 18 657 c) 23 157 d) 23 652

Answers

Answer:

a 23 607

Step-by-step explanation:

Which of the following is equivalent equation

Answers

Answer:

Option 1 F

Step-by-step explanation:

If all the terms in an equation have a common factor, then you can divide all the terms by that common factor and receive the same answer. In this question, all the terms are divisible by 3 (3, 12 and 6 can all divide by 3) so we can divide them all by 3 while keeping the equation equal, which gives us:

3y/3 = 12x/3 -6/3

y = 4x - 2

Hope this helped!

I don't get it can u please show me how to do it step by step ​

Answers

the first one would be
x-6=5
x-6=-5
x=11
x=1
so the answer would be x1 = 1, x2 = 11

Step-by-step explanation:

6.)

|x - 6| = 5

x + 6 = 5

x = 5 - 6

x = - 1

7.)

|3x - 7| = 12

3x + 7 = 12

3x = 12 - 7

3x = 5

x = 5/3

8.)

|2x + 9| - 10 = 5

2x + 9 - 10 = 5

2x - 1 = 5

2x = 1 + 5

2x = 6

x = 6/2

x = 3

Let the universal set be the set of integers and let A​ = {x​ | ​≤ 5}. Write A using the roster method.

Answers

Answer: A = {..., -1, 0, 1, 2, 3, 4, 5}

Step-by-step explanation:

We have that the set A is the set of all the integers equal to or smaller than 5.

To write in the Roster Method, we must list all the elements of this set, but we know that this set extends to minus infinity, then we should start with an ellipsis:

A = {...

Which means that it continues in that direction.

Then we can implicitly write the end of our set, and also some of the points so we can know the relation between the points in the set.

A = {..., -1, 0, 1, 2, 3, 4, 5}

And that is the set A in written with the Roster Method

How many solutions will there be for a quadratic equation of the form ax2 + bx+c = 0 if the discriminant, b2 - 4ac, is negative?
1.)There will be two complex solutions.
2.)There will be one real solution.
3.)There will be two real solutions.
3.)There will be no solutions.

Answers

the first one ..........

7x- 8y = -12
-4x + 2y = 3

Answers

Answer:

Step-by-step explanation:

7x - 8y = -12

-16x + 8y = 12

-9x = 0

x = 0

-4(0) + 2y = 3

2y = 3

y = 3/2

(0, 3/2)

Astronauts who traveled to the moon were able to float slightly as they walked along its surface. Why wee the astronauts able to do this?

Answers

Answer:

C.

Step-by-step explanation:

the farther you get from Earth, the less the gravitational force i, so if your in space, you will have more weight next to earth than you will next to the moon.

The battery in camilles old phone can’t last for 4.2 hours .she bought a new phone that’s gas battery that can last 60% longer . How long can the battery on camilles new phone last?

Answers

Answer:

6.72 Hours

Step-by-step explanation:

Since the new phone can last 60% Longer than 4.2 hours, we multiply 4.2 by .6 and then add it back to 4.2

4.2 X 60% = 2.52

2.52+4.2=6.72

Therefore, the new phone can last 6.72 hours

Evaluate g(x) = x2 + 5 given the inputs (-1,0,1,2}

Answers

Answer:

g(-1) = 6

g(0) = 5

g(1) = 6

g(2) = 9

Step-by-step explanation:

Step 1: Plug in -1 for x

g(-1) = (-1)² + 5

g(-1) = 1 + 5

g(-1) = 6

Step 2: Plug in 0 for x

g(0) = 0² + 5

g(0) = 0 + 5

g(0) = 5

Step 3: Plug in 1 for x

g(1) = 1² + 5

g(1) = 1 + 5

g(1) = 6

Step 4: Plug in 2 for x

g(2) = 2² + 5

g(2) = 4 + 5

g(2) = 9

For each of the following quadrilaterals, Write all the properties that must be true. Four Right angles Only One pair of parallel sides Two pairs of parallel sides All sides congurantParallelogramSquareRhombus

Answers

Answer:

Step-by-step explanation:

THE PROPERTIES:

A. Four right angles

B. Only 1 pair of parallel sides

C. Two pairs of parallel sides

D. All sides congruent - all sides having the same shape and size

FOR A PARALLELOGRAM,

Property C applies

FOR A SQUARE,

Properties A, C and D apply

FOR A RHOMBUS,

Properties C and D apply

Please helps What is the base and the exponent of [tex]7^4[/tex]

Answers

Answer:

Base: [tex]7[/tex]

Exponent: [tex]4[/tex]

Step-by-step explanation:

What is the base and the exponent of [tex]7^4[/tex]?

If you want to know the base, you will have to look at the whole number. The whole number is 7. So that means the base is 7. The number on top of the whole number(exponent) is gonna be the exponent. The number 4 is on the exponent. So in that case, the number 4 is the exponent. So the base is 7 and the exponent is 4.

Hope this helps!

Answer:

Base(7)

Exponent(4)

Step-by-step explanation:

A base is always the whole number. In this exponent, the whole number you see is 7. So that means 7 is the base number. The exponent is the small number you see on top of the whole number(base). The exponent on top of the whole number is 4. So the base number is 7 and the exponent is 4.

Hope this helped you a lot!

Identify each of the following variables as categorical or quantitative.(a) Blood type of a randomly selected person. (b) Amount of snow (in inch) of the next snow storm in Ottawa (c) Daily exchange rate of Canadian dollar versus US dollar (d) The number of car accidents in Ottawa area tomorrow

Answers

Answer:

Step-by-step explanation:

A

Help me please 2(x-4) = 6x - 6

Answers

Answer:

-1/2 = x

Step-by-step explanation:

2 (x - 4) = 6x - 6 (distribute)

2x - 8 = 6x - 6 ( subtract 2x from each side)

- 8 = 4x - 6 ( add 6 to both sides)

-2 = 4x ( divide each side by 4)

x = -2/4 which simplifies to -1/2

Answer:

x is -1/2   (negative one half)

Step-by-step explanation:

Apply distributive property on the left in order to get rid of the parenthesis, and then group all terms in x on the right, and all numerical terms on the left. Combine like terms, and finally solve for "x":

2 (x - 4) = 6 x - 6

2 x - 8 = 6 x - 6

6 - 8 = 6 x - 2 x

-2 = 4 x

x = -2/4

x = -1/2

42 ÷ [15 − (3 + 5)]
help me on this tricky problem

Answers

Answer:

6

Step-by-step explanation:

42 / [15 - (3 + 5)]

42 / [15 - 8]

42 / 7

Answer: 6

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