I'm not quite understanding how to solve these word problems

Mathematics

1 answer:

scoundrel [369]4 years ago

6 0

I'll help you on the first one.
Anya test scores are 78 and 91.
She has one more test and want to average between an 80-89 inclusive.
Lets set up a inequality and call the remaining test x.
80<=(78+91+x)/3<=89
Multiply everything by 3
240<=169+x<=267
Subtract 169 from everything
71<=x<=98
In interval notation that would be [71,98]
In set notation that would be{x|71<=x<=98}
For the graph, I don't really understand. I think you just graph 71<=x<=98.

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books to bookmarks
books : bookmarks
10 : 1
10 * 3 : 1 * 3
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Since the book store sold 30 books they also sold 3 bookmarks.

Answer: 3 bookmarks

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Solving:

1)

-58 - 6x = 42 + 4x
Pass the numbers with letter to the left and the numbers without letter to the right, changing the signal as they change sides.
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10x = - 100
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Pass the numbers with letter to the left and the numbers without letter to the right, changing the signal as they change sides.
5x + 2x = - 33 - 37
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$\boxed{x = - 10}$

3)

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Pass the numbers with letter to the left and the numbers without letter to the right, changing the signal as they change sides.
- 9x + 6x = - 39 - 27
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The sum of the squares of three consecutive positive integers is 7805. What is the sum of the cubes of the three original intege

Vitek1552 [10]

Answer:

398259

Step-by-step explanation:

Let from the given positive integers, x be the smallest integers,

Also, numbers are consecutive,

So, the second integer = x + 1,

Third integer = x + 2,

According to the question,