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kow [346]
3 years ago
10

The sum of 21 and a number is 30

Mathematics
1 answer:
vagabundo [1.1K]3 years ago
5 0
The answer is 9, because you subtract 21 from 30 and you get 9. When you add 21+9 you get 30.
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A scientist needs 4.8 liters of a 12% alcohol solution. She has available a 22% and a 10% solution. How many liters of the 22% a
yanalaym [24]

Answer:

  • 4.0 L of 10%
  • 0.8 L of 22%

Step-by-step explanation:

For mixture problems, it is convenient to define a variable to represent the amount of the greatest contributor. Let x represent the amount of 22% solution in the mix. Then 4.8-x is the amount of 10% solution.

The amount of alcohol in the mix is ...

  0.22x +0.10(4.8-x) = 0.12(4.8)

Eliminating parentheses, we have ...

  0.22x -0.10x +0.10(4.8) = 0.12(4.8)

Subtracting (0.10)(4.8) and combining x-terms gives ...

  0.12x = 0.02(4.8)

  x = (0.02/0.12)(4.8) = 0.8 . . . . . divide by the x-coefficient

The scientist needs 0.8 L of 22% solution and 4.0 L of 10% solution.

5 0
3 years ago
Adam bought A new pair of baseball cleats for $65 the sales tax is 5.5% what is the total cost in dollars that Adam will pay
Dmitry [639]
(65×5.5%)+65 = 68.575
8 0
3 years ago
How do you right 0.0001 in expanded form
kirza4 [7]

The expanded form of the number 0.0001 is \bold{\frac{1}{10000}}.

<u>SOLUTION: </u>

Given that, we have to write 0.0001 in expanded form.

Expanded form or expanded notation is a way of writing numbers to see the math value of individual digits. When numbers are separated into individual place values and decimal places they can also form a mathematical expression.

Now, take the given number 0.0001

As there are no other digits except 0 in front of 1 our work is simplified.

Expanded form will be \frac{1}{10000}

Hence, the expanded form of the number 0.0001 is \frac{1}{10000}.  

4 0
2 years ago
IM HOMESCHOOLED AND I NEED SOME HELP WITH THIS QUESTION. ANYONE PLEASE HELP. my teacher won’t help me :(
gtnhenbr [62]

Answer:

GI = 18;   GE = 12; IE = 6

Step-by-step explanation:

The key to the question is to realize or find out what a centroid is and what it does. You can solve this question by knowing three things.

  1. The centroid is the meeting point of the three medians ( a median is a line that connects the midpoint of the side opposite a given vertex).
  2. The centroid divides the median in a ratio of 2:1. The longest segment is from the vertex to the centroid.
  3. The shortest segment is from the centroid to the midpoint of the side opposite the given vertex.

Point two is what you have to focus on.

GE/EI = 2/1

GE = 12                        Given

Solution

GE / EI = 2/1                 Substitute for the given    

12 / EI = 2/1                  Cross multiply

2*EI = 12 * 1                  Simplify the right

2 * EI = 12                     Divide by 2      

EI = 12/2                        Divide

Part Two

GI = EI + GE

GI = 6 + 12

GI = 18  

EI = 6

4 0
3 years ago
please help me please please please please please please please please please please please please please please please please p
IRISSAK [1]

Answer:

3.) 7

4.) 5

5.) 25

6.) 2/3

7.) 9

8.) 24

5 0
3 years ago
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