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3 years ago

Solve x2-14x+21=0 by completing the square

1 answer:

4 0

$x^2-14x+21=0\\\\x^2-2x\cdot7+7^2-7^2+21=0\\\\(x-7)^2-49+21=0\\\\(x-7)^2-28=0\\\\(x-7)^2=28\iff x-7=-\sqrt{28}\ \vee\ x-7=\sqrt{28}\\\\x=7-\sqrt{4\cdot7}\ \vee\ x=7+\sqrt{4\cdot7}\\\\x=7-2\sqrt7\ \vee\ x=7+2\sqrt7$

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Micah made a scale model of the Empire State building.The building has an actual height of 381 meters. Micah’s model used a scal

Marysya12 [62]

Answer:

1cm = 50

2 cm = 50 x 2

3cm = 50 x 3

and the inverse:50m = 50/50 = 1cm

100m = 100/50 = 2cm

150m = 150/50 = 3cm

381m = 381/

3 0

3 years ago

(05.01)Which equation can be used to calculate the area of the shaded triangle in the figure below?

Lemur [1.5K]

2nd one, take area of whole 12 x 4=48, if area is equally divided, divide area by 2 or multiply by 1/2

7 0

3 years ago

Read 2 more answers

Suppose the probability of producing a defective light bulb from a production line is the same over an interval of 90 minutes. W

butalik [34]

Answer:

C) Uniform distribution

Step-by-step explanation:

An uniform probability is a case of probability in which each outcome is equally as likely. In this case, the probability of producing a defective light bulb from a production line is the same over an interval of 90 minutes, so the correct answer is C.

We can calculate the probability.

Uniform probability distribution

For this situation, we have a lower limit of the distribution that we call a and an upper limit that we call b.

The probability that we find a value X lower than x is given by the following formula.

$P(X \leq x) = \frac{x - a}{b-a}$

For this problem, we have that:

Uniformily distributed over a 90 minute interval, that is, between 0 and 90, so $b = 90$ and $a = 0$ .

We want to find $P(X \leq 15) = \frac{15-0}{90-0} = 0.167$

8 0

3 years ago

3(4+2)=30 pls help me

vladimir1956 [14]

Answer:

Isn't it 18?

Step-by-step explanation:

Because you need to add 4 and 2 then multiply it with 3?

5 0

3 years ago

In a group of 25 students, 6 study both Art and Biology. 10 study Biology but not Art. 3 study neither subject. Given that a ran

olga2289 [7]

Answer:

1/2

Step-by-step explanation:

There are a total of 25 students. 3 don't study art or biology. 10 study only biology. 6 study both art and biology. This means the remaining students only study art.

1. Calculate the number of students taking art

only art: 25 - 3 - 6 - 10 = 6

number of students taking art and biology: 6

total number of students taking art: 12

2. Calculate the probability

Out of the 12 total students taking art, 6 are in art and biology.

6/12 = 1/2

6 0

3 years ago