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Zanzabum
4 years ago
7

How can you find 5% of any number using mental math?

Mathematics
2 answers:
Kryger [21]4 years ago
8 0

Answer:

Step-by-step explanation:

I'm not sure my way is going to be any quicker or better. Let's take an example.

Suppose you start with 456

Put a decimal at the end of the 6.   You get 456.

Shift the decimal to the left one place           45.6

Divide by 2

22.8 (done mentally)

Note: dividing by 2 is easier than dividing by 5. Or multiplying by 5 for that matter.

Check the result.

456 * 5/100 =2280 / 100.

Shift a decimal 2 places to the left.

22.80 which agrees with your result.

Natalija [7]4 years ago
7 0
Just take 10% of the number and divide that by 2. Taking 10% of a number is easy, for example, 10% of 100 is 10, 10% of 45 is 4.5 - you simply move the decimal point over 1. Once you take the 10% just divide it by two and you get 5%.
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I have a favorite quadratic equation. You tell me a pair of numbers (x, y) and I'll tell you if I like that pair of numbers or n
larisa [96]

Answer:

Is it 2x² + 2x + 2?

Step-by-step explanation:

Check the picture...

8 0
3 years ago
A _______ is a set of characters that uses the same typeface.
eimsori [14]
A font is a set of characters that uses the same typeface.It is a specific typeface of a fix size and style. An example is, a font may be Arial 12 pt bold, while another font may be Times New Roman 14 pt italic. According to Merriam dictionary, font is an assortment or set of type or charactersall of one style and sometimes one size.
4 0
3 years ago
Given f(x) = x² - 10x + 22, what is the range of f?
adoni [48]

Answer:

[-3, ∞)

Step-by-step explanation:

There are many ways to find the range but I will use the method I find the easiest.

First, find the derivative of the function.

f(x) = x² - 10x + 22

f'(x) = 2x - 10

Once you find the derivative, set the derivative equal to 0.

2x - 10 = 0

Solve for x.

2x = 10

x = 5

Great, you have the x value but we need the y value. To find it, plug the x value of 5 back into the original equation.

f(x) = x² - 10x + 22

f(5) = 5² - 10(5) + 22

      = 25 - 50 +22

      = -3

Since the function is that of a parabola, the value of x is the vertex and the y values continue going up to ∞.

This means the range is : [-3, ∞)

Another easy way is just graphing the function and then looking at the range. (I attached a graph of the function below).

Hope this helped!

6 0
3 years ago
A sine function has the following key features: Period = 4 Amplitude = 3 Midline: y=−1 y-intercept: (0,-1) The function is not a
mezya [45]

Answer:

  • See the graphs attached and the explanation below

Explanation:

The most simple sine function, considered the parent function, is:

     y=sin(x)

That function has:

  • Midline, also known as rest or equilibrium position: y = 0
  • Minimum: - 1
  • Maximum: 1
  • Amplitude: the distance between a minimum or a maximum and the midline = 1
  • period: the interval of repetition of the function = 2π

The more general sine function is:

             y=Asin(Bx+C)+D

That function has:

  • Midline: y = D (it is a vertical shift from the parent function)
  • Minimum: - A + D
  • Maximum: A + D
  • Amplitude: A
  • period: 2π/B
  • phase shift: C (it is a horizontal shift of the from the parent function)

Now, you have to draw the sine function with the given key features:

  • Period = 4 ⇒ 2π/B = 4 ⇒ B = π/2
  • Amplitude, A = 3
  • midline y = - 1 ⇒ D = - 1
  • y-intercept = (0, -1)

Substitute the know values and use the y-intercept to find C:

       

            y=3sin(2x/\pi+C)-1

Substitute (0, -1)

             

              -1=3sin(0+C)-1\\ \\ 3sin(C)=0\\ \\ sin(C)=0\\ \\ C=0

Hence, the function to graph is:

              y=3sin(\pi x/2)-1

To draw that function use this:

  • Maxima: 3(1) - 1 = 3 - 1 = 2, at x = 1 ± 4n (n = 0, 1, 2, 3, ...)
  • Minima: 3(-1) - 1 = - 3 - 1 = -4
  • y-intercept: (0, - 1)
  • x-intercepts: the solutions to 0 = 3sin(πx/2) = - 1
  • first point of the midline: (0, -1) it is the same y-intercept

With that you can understand the graphs attached.

4 0
3 years ago
-1/3 + 7/4. in simplest form plzz
Goryan [66]
Greatest Common Factor: 12-1/3 = -4/12, 7/4 = 21/12-4/12 + 21/12 = 17/12
Answer in simplest form: 17/12
7 0
3 years ago
Read 2 more answers
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