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3 years ago

When is 9+10 really equal to 21

Mathematics

2 answers:

schepotkina [342]3 years ago

4 0

Answer:

9 + 10 = 21

Step-by-step explanation:

9 + 10 = 21

Factor out 9 and 10

9 = 3 · 3 10 = 2 · 5

Next multiply 3 by 2

3 × 2 = 6

Then multiply 3 by 5

3 · 5 = 15

Finally add the products

15 + 6 = 21

Aleksandr [31]3 years ago

4 0

It can never be equal to 21 because that’s not how math works

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Since there are two of 112 blocks, it will be 112 ÷ 2

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5.44 Teaching descriptive statistics: A study compared five different methods for teaching descriptive statistics. The five meth

maria [59]

Answer:

The null hypothesis is that all the different teaching methods have the same average test scores.

H0: μ1 = μ2 = μ3 = μ4 = μ5

The alternative hypothesis is that at least one of the teaching methods have a different mean.

Ha: at least one mean is different. (μ1 ≠ μi)

Step-by-step explanation:

The null hypothesis (H0) tries to show that no significant variation exists between variables or that a single variable is no different than its mean. While an alternative Hypothesis (Ha) attempt to prove that a new theory is true rather than the old one. That a variable is significantly different from the mean.

For the case above, let μ represent the average test scores for the teaching methods:

The null hypothesis is that all the different teaching methods have the same average test scores.

H0: μ1 = μ2 = μ3 = μ4 = μ5

The alternative hypothesis is that at least one of the teaching methods have a different mean.

Ha: at least one mean is different. (μ1 ≠ μi)

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2 years ago

5. Priya mixes 2..5 cups of water with 1/3 cup or orange juice concentrate. Diego mixes 1 2/3 cups of water with 1/4 cup or oran

Snowcat [4.5K]

Priya needs 13⅓ cups of orange juice

Diego 15 cups

Step-by-step explanation:

......................................................................................................................

Priya

......................................................................................................................

Cup of water = 2½

Cup of orange = ⅓

If 2½ cups of water requires ½ cup of orange juice concentrate

Then 100 cups of water would require x cup of orange

Representing the above statement mathematically

2½ : ⅓ = 100 : x

5/2 : 1/3 = 100 : x ------------------Convert ratio sign to division

5/2 ÷⅓ = 100/x

5/2 * 3 = 100/x

15/2 = 100/x ---------------Multiply both sides by x

15/2 * x = 100/x * x

15x/2 = 100 ------------------ Multiply both sides by 2

2 * 15x/2 = 2 * 100

15x = 200 --------------- Divide both sides by 15

x = 200/15

x = 13⅓

So, 13⅓ cups of orange is needed by Priya

......................................................................................................................

Diego

......................................................................................................................

Cup of water = 1⅔

Cup of orange = ¼

If 1⅔ cups of water requires ¼ cup of orange juice concentrate

Then 100 cups of water would require x cup of orange

Representing the above statement mathematically

1⅔:¼ = 100:x

5/3 : ¼ = 100:x

5/3 ÷¼ = 100 ÷ x

5/3 * 4/1 = 100 ÷ x

20/3 =100/x----------------------- Multiply x to both sides

20/3 * x = 100/x * x

20x/3 = 100 ------------------------ Multiply 3 to sides by 3

3 * 20x/3 = 100 * 3

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x = 15

So, 15 cups of orange is needed by Diego

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3 years ago

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ryzh [129]

Answer:

672 square inches

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1 year ago

Help and explain thanks!

katen-ka-za [31]

Answer:

120 cm

Step-by-step explanation:

One way to tackle this is by getting another sheet of paper and drawing it out, then counting up the total of the sides. If you draw it, you can see that you're dealing with a rectangle; two sides of length 12 and two sides of length 8. If you don't like drawing or don't want to in this case, another way to get the answer is by knowing one vertex is at (0, 0), so the next vertex (0, 8), would create a side that's exactly 8 units long. Kind of the same, you know from (0, 0), you also have a point (12, 0), so drawing that would create a side that's 12 units long. All in all, to get the perimeter in units, you have 12 + 12 + 8 + 8 = 40.

The problem says it wants the amount of wood in centimeters needed for the perimeter. What we just found was the perimeter in generic units, so if the problem says every "grid square", or unit, is 3 centimeters long, then all you have to do is take our result 40 and multiply it by 3 to get the number of centimeters. Your perimeter in centimeters would be 120 cm.

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