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3 years ago

8

The Sanchez family drove 132 miles in 3 hours before lunch. Then they drove 240 miles in 5 hours after lunch.

1 answer:

lilavasa [31]3 years ago

3 0

The formula for speed is the total distance traveled over time. We shall calculate the 2 speeds individually- before and after lunch. Afterwhich, we shall add them together and divide by 2 to get the average.
Before lunch s = 132 mi / 3 hr = 44 mi/hr
After lunch s = 240 mi / 5 hr = 48 mi/hr

Ave s= 48 + 44 / 2
Ave s= 46 mi/hr

Therefore the correct answer is A.

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Find the perimeter and area of the polygon with the given vertices W(5,-1), X (5, 6), Y (2, -1), Z (2,6)

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3 years ago

sin alpha = 7/25, alpha lies in quadrant ii, and cos beta = 2/5, beta lies in quadrant i. find cos(alpha-beta).

Ilia_Sergeevich [38]

Answer:

Therefore $\cos(\alpha-\beta)=\frac{48+7\sqrt{25}}{125}$

Step-by-step explanation:

Given values are

$\sin \alpha=\frac{7}{25}$

$\cos \beta=\frac{2}{5}$

$\sin^2x+\cos^2=1$

$\cos \alpha=\sqrt{1-\sin^2\alpha}$

$\cos \alpha=\sqrt{1-(\frac{7}{25})^2}$

$\cos \alpha=\sqrt{1-\frac{49}{625}}$

$\cos \alpha=\sqrt{\frac{576}{625}}$

$\cos \alpha=\frac{24}{25}$

$\sin \beta=\sqrt{1-\cos^2\beta}$

$\sin \beta=\sqrt{1-(\frac{2}{5})^2}$

$\sin \beta=\sqrt{1-\frac{4}{25}}$

$\sin \beta=\frac{\sqrt{21}}{5}$

$\cos(\alpha-\beta)=\cos\alpha\cos\beta+\sin\alpha\sin\beta$

$\cos(\alpha-\beta)=\frac{24}{25}\times\frac{2}{5}+\frac{7}{25}\times\frac{\sqrt{21}}{5}$

$\cos(\alpha-\beta)=\frac{48+7\sqrt{25}}{125}$

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3 years ago

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Step-by-step explanation:

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3 years ago

Read 2 more answers

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3 years ago

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Answer:

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Is the answer

Step-by-step explanation:

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That is why

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And

$( - 2) \times 3a = ( - 6)$

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3 years ago