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3 years ago

The average of two numbers is 25 and their difference is 8. What are the numbers?

1 answer:

8 0

$x;y-the\ numbers\\\\ \left\{\begin{array}{ccc}\frac{x+y}{2}=25&|multiply\ both\ sides\ by\ 2\\x-y=8\end{array}\right\\+\left\{\begin{array}{ccc}x+y=50\\x-y=8\end{array}\right\ \ \ |add\ sides\ of\ the\ equations\\---------\\.\ \ \ \ \ \ \ \ 2x=58\ \ \ \ \ \ \ |divide\ both\ sides\ by\ 2\\.\ \ \ \ \ \ \ \ \ \ x=29\\\\29+y=50\\y=50-29\\y=21\\\\Answer:29\ and\ 21.$

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Complete the table of values

Agata [3.3K]

Both problems give you a function in the second column and the x-values. To find out the values of a through f, you need to plug in those x-values into the function and simplify!

You need to know three exponent rules to simplify these expressions:
1) The negative exponent rule says that when a base has a negative exponent, flip the base onto the other side of the fraction to make it into a positive exponent. For example, $3^{-2} =
\frac{1}{3^{2} }$ .
2) Raising a fraction to a power is the same as separately raising the numerator and denominator to that power. For example, $(\frac{3}{4}) ^{3} = \frac{ 3^{3} }{4^{3} }$ .
3) The zero exponent rule says that any number raised to zero is 1. For example, $3^{0} = 1$ .


Back to the Problem:
Problem 1
The x-values are in the left column. The title of the right column tells you that the function is $y = 4^{-x}$ . The x-values are:
1) x = 0
Plug this into $y = 4^{-x}$ to find letter a:
$y = 4^{-x}\\
y = 4^{-0}\\
y = 4^{0}\\
y = 1$

2) x = 2
Plug this into $y = 4^{-x}$ to find letter b:
$y = 4^{-x}\\ 
y = 4^{-2}\\ 
y = \frac{1}{4^{2}} \\ 
y= \frac{1}{16}$

3) x = 4
Plug this into $y = 4^{-x}$ to find letter c:
$y = 4^{-x}\\ 
y = 4^{-4}\\ 
y = \frac{1}{4^{4}} \\ 
y= \frac{1}{256}$


Problem 2
The x-values are in the left column. The title of the right column tells you that the function is $y = (\frac{2}{3})^x$ . The x-values are:
1) x = 0
Plug this into $y = (\frac{2}{3})^x$ to find letter d:
$y = (\frac{2}{3})^x\\
y = (\frac{2}{3})^0\\
y = 1$

2) x = 2
Plug this into $y = (\frac{2}{3})^x$ to find letter e:
$y = (\frac{2}{3})^x\\ y = (\frac{2}{3})^2\\ y = \frac{2^2}{3^2}\\
y = \frac{4}{9}$

3) x = 4
Plug this into $y = (\frac{2}{3})^x$ to find letter f:
$y = (\frac{2}{3})^x\\ y = (\frac{2}{3})^4\\ y = \frac{2^4}{3^4}\\ y = \frac{16}{81}$

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Answers:
a = 1
b = $\frac{1}{16}$ 
c = $\frac{1}{256}$
d = 1
e = $\frac{4}{9}$
f = $\frac{16}{81}$

5 0

3 years ago

Name and describe the methods for determining a marketing budget.

Mekhanik [1.2K]

Answer: There are several ways in which we can determine our marketing budget. Some of these are given below:

1. Percentage of revenues:

Under this method we usually take a fixed percentage of our revenues and further allocating this amount for marketing. We will choose the percentage that works best for us.

2. Percentage of net sales:

This method determines our marketing budget as a fraction of our net sales. This method will take a lot of trial and error to find the percentage that works well for our company.

3. Industry specific:

Nowadays, industries have specific projections as to the amount they will need to spend on marketing . The best way to get these numbers is to find a firm that represents our industry and ask them to provide us with averages. We can then refine the actual costs.

4. Objective/task oriented 

This is model that works by setting out goals, planning out the tasks and then estimating the cost for all of these tasks. It works greatly for firms who have a immense knowledge about measurements and information of their business processes.

4 0

3 years ago

0.5 is what type of number?

zepelin [54]

0.5 is a rational number.

4 0

2 years ago

Read 2 more answers

2x + 6 = x – 1 Real solutions

pogonyaev

Answer:

x = -7

Step-by-step explanation:

2x+6 = x-1

add -6 to both sides

2x = x-7

add -x to both sides

x = -7

6 0

3 years ago

The head of maintenance at XYZ Rent-A-Car believes that the mean number of miles between services is 2135 miles, with a variance

stiv31 [10]

Answer:

0.36878

Step-by-step explanation:

Given that:

Mean number of miles (m) = 2135 miles

Variance = 145924

Sample size (n) = 40

Standard deviation (s) = √variance = √145924 = 382

probability that the mean of a sample of 40 cars would differ from the population mean by less than 29 miles

P( 2135 - 29 < z < 2135 + 29)

Z = (x - m) / s /√n

Z = [(2106 - 2135) / 382 / √40] < z < [(2164 - 2135) / 382 / √40]

Z = (- 29 / 60.399503) < z < (29 / 60.399503)

Z = - 0.4801364 < z < 0.4801364

P(Z < - 0.48) = 0.31561

P(Z < - 0.48) = 0.68439

P(- 0.480 < z < 0.480) = 0.68439 - 0.31561 = 0.36878

= 0.36878

3 0

2 years ago