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sergeinik [125]
1 year ago
15

The triangle DEF is shown in the diagram.Find the exact value of x.​

Mathematics
1 answer:
vladimir1956 [14]1 year ago
8 0

Answer:

x = 4

Step-by-step explanation:

Using cosine triangle formula, we know that;

c² = a² + b² - 2ac(cos C)

From our diagram;

a = 2x

b = x + 1

c = 7

C = 60°

Thus;

7² = (2x)² + (x + 1)² - 2(2x)(x + 1)cos 60

49 = 4x² + (x² + 2x + 1) - (4x² + 4x)(0.5)

49 = 5x² + 2x + 1 - 2x² - 2x

3x² + 1 - 49 = 0

3x² - 48 = 0

3x² = 48

x² = 48/3

x² = 16

x = √16

x = 4

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Arc CD is One-fourth of the circumference of a circle. What is the radian measure of the central angle?
Alex

Answer:

\frac{\pi }{2}

Step-by-step explanation:

Since the arc is \frac{1}{4} of the circumference, then

central angle = \frac{1}{4} × 2π ← angle in whole circle

central angle = \frac{2\pi }{4} = \frac{\pi }{2}

8 0
2 years ago
a water tank holds 24,000 gallons how many hours will it take for two thirds of the water to be used if the water is used at an
melomori [17]
In this question there are several important information's worth noting.Based on these information's the answer can be easily found. It is given that the total capacity of the tank is 24000 gallons. in 24 hours or in 1 day the amount of water used is 650 gallons. The question requires us to find the time it will take to use 2/3 rd of the water in the tank.
then
2/3 rd water in respect to total water in tank = (2/3) * 24000
                                                                       = 16000
So 2/3 rd water of full tank is equivalent to 16000 gallons.
Now
650 gallons of water is used in = 24 hours
So
16000 gallons of water will be used in = (24/650) * 16000
                                                             = 590.77 hours
So it will take 590.77 hours to consume 2/3rd of the total water present in the tank.
6 0
1 year ago
Taylor bought 6 tickets to a movie. The price of each ticket was the same. After he bought the tickets, his account balance show
Sladkaya [172]

It is -11.34

-$68.04 divide by 6 is -$11.34, so instead of 11.34, it's -11.34

3 0
1 year ago
Linda commutes a total of 54 miles to and from work every day. She needs a new car, and good gas mileage is important to her. Sh
Alchen [17]
The answer is 1 gallon.

Miles per gallon(mpg) is computed by dividing the distance traveled by the how many gallons used. So you can derive a formula for how many gallons you would use given the mpg. You will end up with:

gallon =  \frac{miles travelled}{miles per gallon}

The problem asks for how many gallons of gas she will safe in a five-day work work week. So first you need to compute how many miles that would be. 

54 miles/day x 5days =  270 miles

So in a five day work week, she will travel 270 miles.

Now to see how much gas she will save, compute how many gallons she will use up for each car, given the mpg of each and find the difference. 

First model:30 mpg

gallons = \frac{270miles}{30mpg}
gallons = 9g
 
This means that with the first model, she will have used up 9 gallons in a 5-day work week.

Second model: 27 mpg
g = \frac{270mi}{27mi/g}
g = 10g

This means that with the second model, she will have used up 10g in a 5-day work week. 

Now for the last bit. How much will she save? You can get that by getting the difference of how many gallons each car would have used up.

10gallons - 9gallons = 1g

So she would have saved 1 gallon of gas if she buys the first car instead of the second. 
 
8 0
1 year ago
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