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3 years ago

Ok I’m actually dumb lol help me please.

Mathematics

1 answer:

mezya [45]3 years ago

3 0

Answer:

x =20

Step-by-step explanation:

As a line is 180 degrees

So 7x + 40 would be 180, which would lead us with the equation:

7x+40=180

=7x =140 (minus both sides by 40)

=x =20 (divide both sides by 7)

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During normal breathing, about 12% of the air in the

nekit [7.7K]

The original air present after 8 breaths will be equal to 179.81 ml.

<h3>What is an equation?</h3>

The equation in mathematics is the relationship between the variables and the number and establishes the relationship between the two or more variables.

It is given in the question that:-

During normal breathing, about 12% of the air in the lungs is replaced after one breath

If the initial amount of air in the lungs is 500 mL

how much of the original air is present after 8 breaths?

The calculation for the eduction of the air will be done by the following equation:-

$\rm =Volume \ present\times (0.88)^n\\\\\\= 500\times (0.88)^8$

=179.88 ml

Hence original air present after 8 breaths will be equal to 179.81 ml.

To know more about equations follow

brainly.com/question/2972832

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2 years ago

You are choosing a song for your dance recital. Song A has 11 beats in 10 seconds. Song B has 7 beats in 6 seconds. Which song h

Fittoniya [83]

Song A has 1 .10 beats/second and song B has 1.16 beats/second so it is song a.

8 0

3 years ago

Find the exact value of sin(cos^-1(4/5))

boyakko [2]

If you're using the app, try seeing this answer through your browser: brainly.com/question/2762144

_______________

Let $\mathsf{\theta=cos^{-1}\!\left(\dfrac{4}{5}\right).}$

$\mathsf{0\le \theta\le\pi,}$ because that is the range of the inverse cosine funcition.

Also,

$\mathsf{cos\,\theta=cos\!\left[cos^{-1}\!\left(\dfrac{4}{5}\right)\right]}\\\\\\
\mathsf{cos\,\theta=\dfrac{4}{5}}\\\\\\ \mathsf{5\,cos\,\theta=4}$

Square both sides and apply the fundamental trigonometric identity:

$\mathsf{(5\,cos\,\theta)^2=4^2}\\\\
\mathsf{5^2\,cos^2\,\theta=4^2}\\\\
\mathsf{25\,cos^2\,\theta=16\qquad\qquad(but,~cos^2\,\theta=1-sin^2\,\theta)}\\\\
\mathsf{25\cdot (1-sin^2\,\theta)=16}$

$\mathsf{25-25\,sin^2\,\theta=16}\\\\
\mathsf{25-16=25\,sin^2\,\theta}\\\\
\mathsf{9=25\,sin^2\,\theta}\\\\
\mathsf{sin^2\,\theta=\dfrac{9}{25}}
$

$\mathsf{sin\,\theta=\pm\,\sqrt{\dfrac{9}{25}}}\\\\\\
\mathsf{sin\,\theta=\pm\,\sqrt{\dfrac{3^2}{5^2}}}\\\\\\
\mathsf{sin\,\theta=\pm\,\dfrac{3}{5}}$

But $\mathsf{0\le \theta\le\pi,}$ which means $\theta$ lies either in the 1st or the 2nd quadrant. So $\mathsf{sin\,\theta}$ is a positive number:

$\mathsf{sin\,\theta=\dfrac{3}{5}}\\\\\\
\therefore~~\mathsf{sin\!\left[cos^{-1}\!\left(\dfrac{4}{5}\right)\right]=\dfrac{3}{5}\qquad\quad\checkmark}$

I hope this helps. =)

Tags: <em>inverse trigonometric function cosine sine cos sin trig trigonometry</em>

3 0

3 years ago

Read 2 more answers

11.1 x 0.8 x 1.16 x 0.4

makkiz [27]

Answer: 4.12032 which is also equivalent to 4:12

3 0

3 years ago

How do I solve this problem?

romanna [79]

Answer:

It will be 3 4/8 or 3 1/2