Hey there!
1. 5(s-2) This is because s-2 is the length of each side, and there are 5 sides in a pentagon all of that length, so multiplying it by 5 like this shows its perimeter.
2. 5s-10 This can be found by distributing the first equation, multiplying both s and -2 by 5.
3. (s-2) + (s-2) + (s-2) + (s-2) + (s-2) Each grouping in the parenthesis represents each of the 5 sides, so adding them all together will get you the perimeter.
4. 5(s) + 5(-2) This one is most like the first one, except it's a little more spread out. Multiply the term s by the 5 sides in one grouping, and the integer -2 by 5 in the other.
Hope this helps!
Answer:
69
Step-by-step explanation:
23 on each shelf x 3 shelves = 69 books
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Answer:</h2>
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Step-by-step explanation:</h2>
This is a square pyramid because it's a solid having a square base. The point up the pyramid is called the apex and is directly above the middle of the square base. The surface area of a solid is the total area of its outer surface. If we unfold this pyramid, we'll get one square and four identical triangles. So the surface are can be calculated as follows:
FOR THE SQUARE:
FOR THE TRIANGLE:
Finally:
The first solution contributes 0.78*1 = 0.78 L of acid.
The second contributes 0.64*6 = 3.84 L of acid.
There will be 7 L total of the new solution, and 3.84 + 0.78 = 4.62 total L of acid in it. So the new solution has a concentration of 4.62/7 = 0.66, or about 66%.
