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3 years ago

Simplify:(-5/8x3/7x4/-15)+(4/7x-21/8)

Mathematics

1 answer:

Ivahew [28]3 years ago

5 0

Answer:

4x/7 - 143/56

Step-by-step explanation:

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Answer:

-7

Step-by-step explanation:

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3 years ago

Read 2 more answers

Could someone please help me:) I am stick and I am not sure what to do

Delicious77 [7]

Answer:

Part 5.1.1:

$\displaystyle \cos 2A = \frac{7}{8}$

Part 5.1.2:

$\displaystyle \cos A = \frac{\sqrt{15}}{4}$

Step-by-step explanation:

We are given that:

$\displaystyle \sin 2A = \frac{\sqrt{15}}{8}$

Part 5.1.1

Recall that:

$\displaystyle \sin^2 \theta + \cos^2 \theta = 1$

Let θ = 2A. Hence:

$\displaystyle \sin ^2 2A + \cos ^2 2A = 1$

Square the original equation:

$\displaystyle \sin^2 2A = \frac{15}{64}$

Hence:

$\displaystyle \left(\frac{15}{64}\right) + \cos ^2 2A = 1$

Subtract:

$\displaystyle \cos ^2 2A = \frac{49}{64}$

Take the square root of both sides:

$\displaystyle \cos 2A = \pm\sqrt{\frac{49}{64}}$

Since 0° ≤ 2A ≤ 90°, cos(2A) must be positive. Hence:

$\displaystyle \cos 2A = \frac{7}{8}$

Part 5.1.2

Recall that:

$\displaystyle \begin{aligned} \cos 2\theta &= \cos^2 \theta - \sin^2 \theta \\ &= 1- 2\sin^2\theta \\ &= 2\cos^2\theta - 1\end{aligned}$

We can use the third form. Substitute:

$\displaystyle \left(\frac{7}{8}\right) = 2\cos^2 A - 1$

Solve for cosine:

$\displaystyle \begin{aligned} \frac{15}{8} &= 2\cos^2 A\\ \\ \cos^2 A &= \frac{15}{16} \\ \\ \cos A& = \pm\sqrt{\frac{15}{16}} \\ \\ \Rightarrow \cos A &= \frac{\sqrt{15}}{4}\end{aligned}$

In conclusion:

$\displaystyle \cos A = \frac{\sqrt{15}}{4}$

(Note that since 0° ≤ 2A ≤ 90°, 0° ≤ A ≤ 45°. Hence, cos(A) must be positive.)

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HELP HELP 100 POINTS!! Paola was given the equation y= -x + 3. Which of following is an equivalent representation of the equatio

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Answer:

a. Is the answer..

Let's solve for y.

y=−x+3

Answer:

y = −x + 3 = y = −x + 3

Hence f(x) = -x + 3 is equivalent to y = −x + 3

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Simplify:(-5/8x3/7x4/-15)+(4/7x-21/8)​

Simplify:(-5/8x3/7x4/-15)+(4/7x-21/8)