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3 years ago

Three angles in a quadrilateral are 65, 80, and 100. Which of the following could be the 4th angle?

Mathematics

1 answer:

Nimfa-mama [501]3 years ago

4 0

All the angles of the quadrilateral have to sum up to 360

So 65 + 80 + 100 = 245 and then 360 - 245 = 115

So its B. 115

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What are the types of roots of the equation below?<br> - 81=0

Tju [1.3M]

Option B, that is Two Complex and Two Real which are x + 3, x - 3, x + 3i and x - 3i, are the types of roots of the equation x⁴ - 81 = 0. This can be obtained by finding root of the equation using algebraic identity.

<h3>What are the types of roots of the equation below?</h3>

Here in the question it is given that,

the equation x⁴ - 81 = 0

By using algebraic identity, (a + b)(a - b) = a² - b², we get,

⇒ x⁴ - 81 = 0

⇒ (x² + 9)(x² - 9) = 0

(x² - 9) = (x² - 3²) = (x - 3)(x + 3) [using algebraic identity, (a + b)(a - b) = a² - b²]
x² + 9 = 0 ⇒ x² = -9 ⇒ x = √-9 ⇒ x= √-1√9 ⇒x = ± 3i

⇒ (x² + 9) = (x - 3i)(x + 3i)

Now the equation becomes,

[(x - 3)(x + 3)][(x - 3i)(x + 3i)] = 0

Therefore x + 3, x - 3, x + 3i and x - 3i are the roots of the equation

To check whether the roots are correct multiply the roots with each other,

⇒ [(x - 3)(x + 3)][(x - 3i)(x + 3i)] = 0

⇒ [x² - 3x + 3x - 9][x² - 3xi + 3xi - 9i²] = 0

⇒ (x² +0x - 9)(x² +0xi - 9(- 1)) = 0

⇒ (x² - 9)(x² + 9) = 0

⇒ x⁴ - 9x² + 9x² - 81 = 0

⇒ x⁴ - 81 = 0

Hence Option B, that is Two Complex and Two Real which are x + 3, x - 3, x + 3i and x - 3i, are the types of roots of the equation x⁴ - 81 = 0.

Disclaimer: The question was given incomplete on the portal. Here is the complete question.

Question: What are the types of roots of the equation below?

x⁴ - 81 = 0

A) Four Complex

B) Two Complex and Two Real

C) Four Real

Learn more about roots of equation here:

brainly.com/question/26926523

#SPJ9

5 0

1 year ago

Solve the following inequality<br> giving brainliest

ivanzaharov [21]

X > 4

divide 6 on both sides hence 24/6 = 4

7 0

2 years ago

Bozena is an ecologist who studies the change in the tiger population of Siberia over time. The relationship between the elapsed

klio [65]

Answer:

every 2 years

Step-by-step explanation:

since it is t/2 for the exponent - thas the answer on khan

6 0

3 years ago

One end of a ramp is raised to the back of a truck 5 feet above the ground. 1 point

sveta [45]

Answer:

38.7°

Step-by-step explanation:

You are basically looking at a triangle with a 90° angle (check picture).

Since we are looking for the ramp's angle and are given the length of the opposite and the hypothenuse, we have to solve the following equation:

$sin (\alpha) = opposite / hypothenuse= 5 ft/8ft$

which is equivalent to

$\alpha = sin^{-1}(5/8)\approx 38.7\deg$

6 0

3 years ago

ACTIVITY 1

aleksklad [387]

Answer:

Question A:

1. 1/2 = 0.5 (Terminating)

2. 5/6 = 0.833333.. (Repeating)

3. 21/3 = 1.6666666.. (Repeating)

Question B:

1. 0.6 = 3/5

2. 1.25 = 5/4 = 1 1/4

3. 0.125 = 1/8

Step-by-step explanation:

A. Write the fraction or mixed number as a terminating or repeating decimal.

In order to convert a fraction into decimal, the numerator has to be divided by denominator.

1. 1/2

The answer is: 0.5 which is a terminating decimal.

2. 5/6

The answer is: 0.833333.. which is a repeating decimal.

3. 2 1/3 (assuming the question is this)

$2\frac{1}{3} = \frac{7}{6} = 1.6666666..$

The answer is 1.6666666.. which is a repeating decimal.

B. Write the terminating decimal as fraction or mixed number i n simplest form.

1. 0.6

$0.6 = \frac{6}{10} = \frac{3}{5}$

2. 1.25

$1.25 = \frac{125}{100} = \frac{5}{4} = 1\frac{1}{4}$

3. 0.125

$0.125 = \frac{125}{1000} = \frac{5}{40} = \frac{1}{8}$

Hence,

Question A:

1. 1/2 = 0.5 (Terminating)

2. 5/6 = 0.833333.. (Repeating)

3. 21/3 = 1.6666666.. (Repeating)

Question B:

1. 0.6 = 3/5

2. 1.25 = 5/4 = 1 1/4

3. 0.125 = 1/8

7 0

3 years ago