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ANEK [815]
3 years ago
9

A piano has white keys and black keys in the ratio of 13 : 9. If there are 52 white keys,how many black keys are there?

Mathematics
2 answers:
Hitman42 [59]3 years ago
5 0
✡ Answer: 9/36 <span>✡
</span><span>
- - Why?

Because if you look at it like this:

</span>\frac{13}{52} =  \frac{9}{36}
<span>
- 52 being the white and 36 because the black.

</span>✡Hope this helps<span>✡</span><span>



</span>
luda_lava [24]3 years ago
3 0
Let w = white and b = black.
Using the proportion,
13/w = 9/b
Since w = 52 white keys, therefore
13/52 = 9/b
b = 36 black keys
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PLEASE HELP ASAP!!!!
Nana76 [90]
The answer is <span>A.) F(x) = 10(2.5)^x</span><span>.

</span>Since our base (2.5) is greater than 1, our graph would be increasing, hence it matches the given graph (it increases to the right, or towards quadrant I). Now all we need to do is solve for the y-intercept:
   F(x) = 10(2.5)^x
   F(0) = 10(2.5)^0 [substitute 0 in for x]
   F(0) = 10(1) [any number raised to 0 would always equal 1]
   y-intercept: 10 
Now does it match the graph? <span><em>Yes, it does.</em>
</span>
Thus, our exponential function for this graph would be F(x) = 10(2.5)^x.
<em /><u>Tip for life</u>: When solving for the y-intercept of exponential functions, our y-intercept is always the number in front of the base (in this case, <u /><u><em>10</em></u>(2.5)^x).

<em>Hope this helps.</em>
7 0
3 years ago
Find how many quarts of 6% butterfat milk and 3% butterfat milk should be mixed to yield 60 quarts of 4% butterfat milk.
Snezhnost [94]

Answer:

20 quarts of 6% butterfat milk and 40 quarts of 3% butterfat milk is used to make 60 quarts of 4% butterfat milk.

Step-by-step explanation:

We are given the following in the question:

Let x quarts of 6% butterfat milk be used and y quarts of 3% butterfat milk be used to make 60 quarts of 4% butterfat milk.

Thus, we can write the equation:

6\%\times x + 3\%\times y = 4\%\times 60\\6x + 3y = 240

Total amount of 3% butterfat milk = 60

Thus, we can write the equation:

x+y = 60

Solving the two equation, we get,

6x + 3y-(3x+3y) = 240 - 3(60)\\3x = 240-180\\3x = 60\\x = 20\\y = 60-20 = 40

Thus, 20 quarts of 6% butterfat milk and 40 quarts of 3% butterfat milk is used to make 60 quarts of 4% butterfat milk.

3 0
3 years ago
Convert 0.33333...in to a fraction
erik [133]

Step-by-step explanation:

Let x = 0.3333333...

Then 10x = 3.3333333....

We have 9x = 3, so x = 3/9 or 1/3.

6 0
3 years ago
Can someone please help me with question 35?
Genrish500 [490]
First you would find the area of the triangle which would be 84×92 then divide that answer by 2.
Then you will find the area of the circle using the given radius 20.5.
Lets work it out.
84×92=7728
7728÷2=3864 ft²
3864 ft² is the area of the backyard including the pool.
A=pi(20.5)²
A=1320.25 ft²
1320.25 ft² is the area of the pool.
Now we have to subtract to get the area of the backyard without the pool.
3864-1320.25=2543.75 ft²
2543.75 ft² is your answer.
Hope This Helps and God Bless!
8 0
3 years ago
Find the value of x when 6-3x=5x-10x+4
tatuchka [14]

Answer:

x= -1

Step-by-step explanation:

6-3x=5x-10x+4

6-3x=-5x+4

-4            -4

2-3x=-5x

+3x  +3x

2=-2

2/-2=-2x/-2

-1=x

7 0
3 years ago
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