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3 years ago

Solve for a. 4/a+4 =-1/a+9

Mathematics

1 answer:

Bad White [126]3 years ago

5 0

Answer:

a = -8

Step-by-step explanation:

you can solve this proportion by cross-multiplying:

4(a + 9) = -1(a + 4)

now distribute to eliminate parentheses

4a + 36 = -1a - 4

5a + 36 = -4

5a = -40

a = -8

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Mrs. Lee randomly surveyed 25 of her 125 students about their pets. Her survey

raketka [301]

Answer:

My figure would have 3 overlapping regions, each representing dogs, cats, or fish. The overlapping parts represent those areas where owners have more than one pet.

Now, we know the number owners that have dogs is 14 (place this number outside one of the 3 large regions and call it dogs. Do the same for cats (10) and fish (5). At this point it's important to remember that only some of the 14 dog owners have only dogs. Same for cats and fish.

In fact, we know that 4 owners have both dogs and cats. So, on the figure where the dog region and cat region overlap, write 4. Do the same where the dog and fish regions overlap and write 3.

What this means is that of the 14 dog owners, 7 of them own more than a dog. So, 7 dog owners own only dogs:

14 - 7 = 7

Use the same approach for each of the other pets:

Cats: 10 owners have cats; 4 have dogs and cats and 1 has a cat and a fish. So, 5 owners have only cats (10 - 5).

Fish: 5 owners have fish; 3 have dogs and fish and 1 has a cat and a fish. So 1 owner has only fish (5 - 4).

Then, in summary:

Owners that have:

Only Dogs - 7

Only Cats - 5

Only Fish - 1

Dogs AND Cats - 4

Dogs AND Fish - 3

Cats AND Fish - 1

The total number of owners that have at least one pet then is:

7 + 5 + 1 + 4 + 3 + 1 = 21

So, since there are 26 total owners, 5 must not own a dog, cat, or fish.

hope it helps!!!!!!!!!!!!!!!!!!!

I put lot's of work into it

4 0

3 years ago

How much will you get paid if you work 28.5 hours for $7.75 per hour?

andrey2020 [161]

Answer:

$220.875

Step-by-step explanation:

For 1 hour you get $7.75

To find how much money you make in 28.5 hours... you multiply the number of hours with the number of dollars.

28.5 * 7.75

$220.875

8 0

3 years ago

Read 2 more answers

Which of the following equations has infinitely many solutions?

Valentin [98]

Answer:

Step-by-step explanation:

If you look at A and you subtract 3x by 4x you get x and you subtract 3 from -7 and you get -10. But if you look at B you do the stuff in the parentheses first and you get 4x+12x+28=16x+28 and they're the same so it's B.

7 0

3 years ago

Mary and Jane both took PSY230 last semester but they were in two different sections taught by different professors. Mary's clas

Greeley [361]

Answer:

Due to the higher z-score, Jane did better in class.

Step-by-step explanation:

Z-score:

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

In this question:

Whoever's grade had the better z-score did better in class.

Mary's:

Mean of 85, standard deviation of 5, grade of 88. This means that $\mu = 85, \sigma = 5, X = 88$ . So