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4 years ago

If 10a+10b=35, what is the average (arithmetic mean) of a and b?

Mathematics

1 answer:

worty [1.4K]4 years ago

6 0

Answer:

1.75

Step-by-step explanation:

If a and b are two numbers, then their arithmetic mean is

$\dfrac{a+b}{2}$

Given:

$10a+10b=35$

Divide this equation by 10:

$a+b=3.5$

Now, divide it by 2:

$\dfrac{a+b}{2}=\dfrac{3.5}{2}\\ \\\dfrac{a+b}{2}=1.75$

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Mary bought a desk on sale for 88.40. This price was 74% less than the original price.

kirill115 [55]

Answer: 340

Step-by-step explanation:

100 - 74 = 26%

26% = .26

x * .26 = 88.4

/.26 /.26

x = 340

check

340 * .74 = 251.6

340 - 251.6 = 88.4

4 0

3 years ago

What is the mean of these numbers? Round to the nearest tenth. 4, 2, 7, 5, 12, 7, 4, 11, 0

Fudgin [204]

The answer is 5.66666 (repentant) because you add up all the numbers and then divide by 9 because you have to still include 0. <span />

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3 years ago

A line with a slope of 10 passes through the point (0,4). What is its equation in

Alexus [3.1K]

Answer:

y=10x+4

Step-by-step explanation:

y-y1=m(x-x1)

y-4=10(x-0)

y-4=10(x)

y-4=10x

y=10x+4

7 0

3 years ago

Give at least five problems solving about area of a sector of a circle.

Katyanochek1 [597]

See below for the examples of sectors and arcs of a circle

<h3>Area of sector of a circle</h3>

The area of a sector is calculated as:

$A = \frac{\theta}{360} * \pi r^2$ ---- when the angle is in degrees

$A = \frac{\theta}{2} *r^2$ ---- when the angle is in radians

Take for instance, we have the following problems involving sector areas

Calculate the area of a sector where the radius of the circle is 7, and

The central angle is 30 degrees
The central angle is π/12 rad
The central angle is 90 degrees
The central angle is π/4 rad
The central angle is 180 degrees

Using the above formulas, the sector areas are:

1. $A = \frac{30}{360}* \frac{22}{7} * 7^2 = 12.83$

2. $A = \frac{\pi}{12} * 7^2 = 12.83$

3. $A = \frac{90}{360}* \frac{22}{7} * 7^2 = 38.5$

4. $A = \frac{\pi}{2} * 7^2 = 38.5$

5. $A = \frac{180}{360}* \frac{22}{7} * 7^2 = 77$

<h3>Examples of arc length</h3>

The length of an arc is calculated as:

$L= \frac{\theta}{360} * 2\pi r$ ---- when the angle is in degrees

$L = r\theta$ ---- when the angle is in radians

Take for instance, we have the following problems involving arc lengths

Calculate the length of an arc where the radius of the circle is 7, and

The central angle is 30 degrees
The central angle is π/12 rad
The central angle is 90 degrees
The central angle is π/4 rad
The central angle is 180 degrees

Using the above formulas, the arc lengths are:

1. $L = \frac{30}{360}* 2 * \frac{22}{7} * 7 = 3.7$

2. $L = \frac{\pi}{12} * 7 = 3.7$

3. $L = \frac{90}{360}*2 * \frac{22}{7} * 7 = 11.0$

4. $L = \frac{\pi}{4} * 7 = 11$

5. $L = \frac{180}{360}*2 * \frac{22}{7} * 7 = 22$

<h3>Examples of the arcs of a circle</h3>

The examples include:

A parabolic path
Distance in a curve
Curved bridges
Pizza
Bows