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3 years ago

David Copperfield did this number trick:

Mathematics

1 answer:

Natasha_Volkova [10]3 years ago

7 0

Amakbssbsbsbsbsbsbsbsbsbsbsbssbsbsbsbsbdvdbsbnsnsjss

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Seven times a number is the same as 12 more than 3 times the number

Brums [2.3K]

Answer:

x=3

Step-by-step explanation:

7x=12+3x

4x=12

x=3

5 0

3 years ago

A shark is swimming 25 feet below the surface of the water. It goes down another 12 feet. What is the new depth the shark is swi

ivolga24 [154]

Answer:

Step-by-step explanation:

You add them to see the new depth

7 0

3 years ago

Find all degree solutions in the interval 0° ≤ θ < 360°. If rounding is necessary, round to the nearest tenth of a degree. Us

xenn [34]

Answer:

$\theta_{1} \approx 30.473^{\textdegree}$

$\theta_{2} \approx 120.473^{\textdegree}$

$\theta_{3} \approx 210.473^{\textdegree}$

$\theta_{4}\approx 300.473^{\textdegree}$

Step-by-step explanation:

The equation needs to be rearranged in terms of one trigonometric function:

$5\cdot \sin 2\theta - 9\cdot \cos 2\theta = 0$

$5\cdot \tan 2\theta - 9 = 0$

$5\cdot \tan 2\theta = 9$

$\tan 2\theta = \frac{9}{5}$

$\theta = \frac{1}{2}\cdot \tan^{-1} \left(\frac{9}{5} \right)$

The tangent function has positive values in the 1st and 3rd Quadrants. Then, the solutions are:

$\theta_{1} \approx 30.473^{\textdegree}$

$\theta_{2} \approx 120.473^{\textdegree}$

$\theta_{3} \approx 210.473^{\textdegree}$

$\theta_{4}\approx 300.473^{\textdegree}$

3 0

3 years ago

Margo paid $550.00 for dance classes. She paid a $50.00 registration fee and $25.00 for each week she was enrolled in the classe

trapecia [35]

Answer:

She enrolled in the dance classes for 20 weeks

Step-by-step explanation:

* Margo paid $550.00 for dance classes

* She paid a $50.00 registration fee

* She paid $25.00 for each week she was enrolled in the classes

* We need to find the number of weeks w she enrolled in the

dance classes

Lets write an equation of these information and solve it

∵ The registration fee = $50

∵ The cost of of each week = $25

∵ The number of weeks = w

She will pay $50 plus $25 times the number of the weeks

∴ She paid in the dance classes = 50 + 25 w

∵ She paid $550 for the dance classes

∴ 50 + 25 w = 550

The equation is 50 + 25 w = 550

Lets solve the equation

∵ 50 + 25 w = 550

Subtract 50 from both sides

∴ 25 w = 500

Divide both sides by 25

∴ w = 20

∵ w represents the number of the weeks

∵ w = 20 weeks

She enrolled in the dance classes for 20 weeks

5 0

3 years ago

You collect a random sample of size n from a population and calculate a 90% confidence interval. Which of the following strategi

Daniel [21]

Answer:

Decrease the sample size.

Step-by-step explanation:

Margin of error is:

ME = CV × √(σ / n)

where σ is the population standard deviation, or:

ME = CV × √(p (1 − p) / n)

where p is the proportion.

In each case, the margin of error is directly proportional to the critical value, and inversely proportional to √n.

Lowering the confidence level will lower the critical value, which will decrease the margin of error. Decreasing the sample size will increase the margin of error.

6 0

4 years ago

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