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2 years ago

What is the value of the product (4 – 2i)(6 + 2i)? 20 – 4i 20 + 16i 28 + 16i 28 – 4i

Mathematics

2 answers:

Darya [45]2 years ago

8 0

(4 – 2i)(6 + 2i)

FOIL

First : 4*6 =24

Outer: 4*2i = 8i

Inner: -2i* 6 = -12i

Last: -2i*2i = -4i^2 =-4(-1) =4

Add together

24+8i-12i+4

28-4i

Answer: 28-4i

Ostrovityanka [42]2 years ago

5 0

Answer:

28-4i

Step-by-step explanation:

There for the answer is D

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a rectangle has a height of n3+4n2+3n and a width of n^3+5n^2 express the area of the entire rectangle

alukav5142 [94]

Given:

It is given that the height of the rectangle is $n^3+4n^2+3n$

The width of the rectangle is $n^3+5n^2$

We need to determine the area of the entire rectangle.

Area of the rectangle:

The area of the rectangle can be determined using the formula,

$A=height \times width$

Substituting the values, we have;

$A=(n^3+4n^2+3n)(n^3+5n^2)$

Multiplying each term within the parenthesis, we get;

$A=n^{3} n^{3}+n^{3} \cdot 5 n^{2}+4 n^{2} n^{3}+4 n^{2} \cdot 5 n^{2}+3 n n^{3}+3 n \cdot 5 n^{2}$

Simplifying, we get;

$A=n^{6}+5 n^{5}+4n^{5}+20 n^{4}+3 n^{4}+15 n^{3}$

Adding the like terms, we have;

$A=n^{6}+9n^{5}+23 n^{4}+15 n^{3}$

Thus, the area of the entire rectangle is $n^{6}+9 n^{5}+23 n^{4}+15 n^{3}$

5 0

2 years ago

Find the absolute value of 3.1+(-6.3)

Sliva [168]

Answer:

3.2

Step-by-step explanation:

First, evalue what's inside of the absolute value:

3.1 + (-6.3) = -3.2

Now, since absolute value means the distance from the number to 0, the absolute value of -3.2 is the negation of -3.2:

|-3.2| = 3.2

7 0

1 year ago

A point in the figure is selected at random. Find the probability that the point will be in the part that is NOT shaded.

Dovator [93]

Answer:

Step-by-step explanation:

So the question really is what is the probability that the point is in the square? You cannot pick something surrounding the circles because you do not know anything about that region.

This is solved by comparing areas. There are 2 full circles there. 1 circle has an area of pi*r^2

Total shaded area = 2 * pi * r^2.

Let r = 3 This is a completely random choice. No matter what number you choose for r, the answer will come out the same. When you get along a little further in math, you will find that you can just use letters.

Total shaded area = 2 * 3.14 * 3^2

Total shaded area = 2 * 3.14 * 9

Total shaded area = 56.55

Total area of the square.

s = 2*r

s = 2*3

s = 6

Area of the square = 6^2 = 36

Total area of both regions = 56.55 + 36 = 92.55

Answer

% = (area of square) * 100% / Total area of both regions

% = 3600 / 92

% = 39%

Obviously the answer I get is not offered. The closest answer is B so I will choose that.

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

This is how this question would be done without using any value for r.

Area of shaded region = 2 pi r^2 = 6.28 r^2

Area of square = d^2 where d = 2r

Area of square = 4 r^2

Total area = 6.28 r^2 + 4r^2 = 10.28 r^2

Area of square to total = (4r^2/10.28 r^2 ) * 100%

Area of square to total (as a %) = 4/10.28 * 100 = 39% which gives the same answer.

7 0

2 years ago

Read 2 more answers

A number, x, rounded to 2 significant figures is 1300 Write down the error interval for x.

nikitadnepr [17]

Answer:

$[1250,1350)$ .

Step-by-step explanation:

It is given that a number, x, rounded to 2 significant figures is 1300.

It is possible if,

1. The value of x is greater than of equal to 1250 and less than or equal to 1300.

i.e., $1250\leq x\leq 1300$ ...(1)

2. The value of x is greater than of equal to 1300 and less than 1350.

i.e., $1300\leq x$ ...(2)

On combining (1) and (2), we get

$1250\leq x < 1350$

1350 is not included in the error interval for x.

Interval notation is $[1250,1350)$ .

Therefore, the error interval for x is $[1250,1350)$ .

7 0

2 years ago

Sandy evaluated the expression below. (negative 2) cubed (6 minus 3) minus 5 (2 + 3) = (negative 2) cubed (3) minus 5 (5) = 8 (3

nasty-shy [4]

Answer:

should be - 8

Step-by-step explanation:

-2*-2=4 4*-2=-8

4 0

2 years ago

Read 2 more answers