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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 years ago
-17+ 1/4 x + 1/4 x + 31 = 24
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<h2><u>Answer:</u></h2><h2><u></u>\boxed{x=20}<u></u></h2><h2><u></u></h2><h2><u>Solution Steps:</u></h2>

______________________________

<h3>1.) Combine like terms:</h3>
  • \frac{1}{4}x+\frac{1}{4}x=\frac{1}{2}x

<em>  - We do this because we need 1 Number/Variable left over. </em>

<u>Equation at the end of Step 1:</u>

  • <u />-17+\frac{1}{2}x+31=24<u />

<em />

<h3>2.) Add −17 and 31:</h3>
  • -17+31=14

<em>  - We do this because we can only have 1 number on each side of the equals. (This doesn't count towards the number connected to the variable.)</em>

<u>Equation at the end of Step 2:</u>

  • <u />14+\frac{1}{2}x=24<u />

<h3>3.) Subtract 14 from both sides:</h3>
  • 14-14= Cancels Out
  • 24-14=10

<em>  - We do this because now we just need the 1 variable and the 1 number on opposite sides of the equal.</em>

<u>Equation at the end of Step 3:</u>

  • <u />\frac{1}{2}x=10<u />

<h3>4.) Multiply both sides by 2:</h3>
  • <em />\frac{1}{2}x<em> </em>× 2=x<em />
  • <em />10<em> </em>× 2=20

<em>  - We multiply by 2 since we have a fraction. In this case the reciprocal is 2 meaning we multiply by 2. </em>

<em></em>

______________________________

4 0
3 years ago
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Amanda [17]

Answer:

Leo´s response to the bully is a response of hurt and embarrassment. He seems sad and doesn´t even directly respond to the bullies ,¨several

students were huddled around Leo's desk... he had red rings around his eyes. He looked up at Hannah and said, "Why are people so mean?"

Explanation:

if Leo had posted something mean online the outcome would only have worsened. If it were him in the bullies shoes and the bully in his, the bully wouldve understood how these mean things make people feel.

Leo´s response to the bully is a response of hurt and embarrassment. He seems sad and doesn´t even directly respond to the bullies ,¨several

students were huddled around Leo's desk... he had red rings around his eyes. He looked up at Hannah and said, "Why are people so mean?"

Explanation:

if Leo had posted something mean online the outcome would only have worsened. If it were him in the bullies shoes and the bully in his, the bully wouldve understood how these mean things make people feel.

Leo´s response to the bully is a response of hurt and embarrassment. He seems sad and doesn´t even directly respond to the bullies ,¨several

students were huddled around Leo's desk... he had red rings around his eyes. He looked up at Hannah and said, "Why are people so mean?"

Explanation:

if Leo had posted something mean online the outcome would only have worsened. If it were him in the bullies shoes and the bully in his, the bully wouldve understood how these mean things make people feel.

Step-by-step explanation:

4 0
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