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Lorico [155]
3 years ago
11

What is the value of (7 + 2i)(3 - i)?

Mathematics
1 answer:
Harrizon [31]3 years ago
7 0
There are two ways to work this out: normal variables or using "imaginary" numbers.

Normal variables:
(7+2i)(3-i)\\(7*3)+[7*(-i)]+(3*2i)+[2i*(-i)]\\21-7i+6i-2i^{2}\\\\21-i-2i^{2}

Imaginary numbers:
Using the result from earlier:
21-i-2i^{2}
Now since i = \sqrt{-1}, then the expression becomes:
21-i-2i^{2}\\21-i-2(\sqrt{-1})^{2}\\21-i+(-2)(-1)\\21-i+2\\\\23-i
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3 mas un numero multiplicado por 2 es lo mismo que 3 veces el numero<br> O
Verdich [7]

Answer:

Qué quieres decir con eso

Step-by-step explanation:

7 0
2 years ago
The perimeter P of a square (measured in inches) is expanding in size at a constant rate of change of 4 inches per inch with res
vivado [14]

Answer:

a. 10 inches

b. 8 inches

c. \frac{dP}{ds} = 4

Step-by-step explanation:

a. At side 0, perimeter is 0*4 = 0 in. At side 2.5 inches, perimeter = 2.5*4 = 10 inches, a change of 10 - 0 = 10 inches

b. At side 1, perimeter is 1*4 = 4 inches. At side 3 inches, perimeter = 3*4 = 12 inches, a change of 12 - 4 = 8 inches.

c. We can express the change in the square's perimeter P in terms of the change in the square's side length s as

\frac{dP}{ds} = 4

6 0
3 years ago
part b is: if the energy release of one earthquake is 10,000 times that of another, how much larger is the Richter scale reading
kotegsom [21]

You could use the information from part A to get B. I'm not sure if you want A or not, so I'll do it as well.

A

Eo = 10^4.4 Joules

E = 2 * 10^15

Formula

M = (2/3) log (E/Eo)

M = 2/3 * log (2 * 10^15/10^(4.4) )

M = 2/3 * log( 7.9621* 10^10)

M = 2/3 * 10.901

M = 7.26735 on the Richter scale. That is a huge amount of energy.

Part B

Suppose that you use Eo and your base. Eo is 10^4.4

Now the new earthquake is E = 10000 * Eo

So what you get now is M = (2/3)* Log(10000 * Eo / Eo )

The Eo's cancel out.

M = 2/3 * log(10000)

M = 2/3 of 4

M = 8/3

M = 2.6667 difference in the Richter Scale Reading. It is still an awful lot of energy.

What this tells you is that if the original reading was (say) 6 then the 10000 times bigger reading would 8.266667

Answer: M = 2.6667


8 0
3 years ago
Read 2 more answers
HELP DUE IN 15 MINS!<br><br> x =??
Alisiya [41]

Answer:

x = 32

Step-by-step explanation:

Using the Secant and Tangent Intersection Theorem we can say;

(x + 18) (18) = 30²

18x + 324 = 900

18x = 576

x = 32

Hope this helps!

5 0
3 years ago
Read 2 more answers
Use long division to find the quotient below (30x^3+4x^2-150) / (6x-10)
Anni [7]

Answer:

The answer is

A.5x^2+9x+15

Step-by-step explanation:

kindly find attached the solving for proper understanding and solution flow.

Given Data

the divisor=  6x-10

dividend= 30x^3+4x^2-150

firstly for us to perform the division we need to re write the dividend and include the missing coefficient of x

dividend =30x^3+4x^2+0x-150

3 0
3 years ago
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