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3 years ago

If f(x)= (2x)^2, how do I find f(-4)? Explain.

Mathematics

2 answers:

spin [16.1K]3 years ago

8 0

Answer:

the answer is 64

Step-by-step explanation:

f(-4) means that x is -4 (in other words it replaces x)

so thatll be f(-4) = (2(-4))^2

solve by PEMDAS (Parenthesis, Exponent, Multiplication, Division, Addtion Subtraction)

meaning 2 times -4 equals -8

-8 raised to the second power is saying -8 times -8 which equals 64

Westkost [7]3 years ago

7 0

Answer:

Step-by-step explanation:

f(4-)=2(-4)^2

2*-4=-8

-8^2=64

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A triangle has an area of 36 square feet. If the height of the triangle is 6 more feet than its base, what is its height and bas

andriy [413]

If b is the base then the height h=b+6. As we have S=bh/2 then
36=b(b+6)/2;
b²+6b-72=0;
D/4=3²+72=81
b₁=-3-9=-12
b₂=-3+9=6.
The base is always positive so b=6, h=6+6=12.
Answer: base=6 ft, height=12 ft.

7 0

3 years ago

The U.S. and many other countries have recently tightened airport security. A sociologist is interested in estimating the propor

melisa1 [442]

Answer:

0.0073 < 0.05, which means that we reject the null hypothesis and conclude that the true proportion of interest is higher than 0.7.

Step-by-step explanation:

Conduct a test to determine whether the true proportion of interest is higher than 0.7.

This means that the null hypothesis is: $H_{0}: p = 0.7$

And the alternate hypothesis is: $H_{a}: p > 0.7$

The test statistic is:

$z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}$

In which X is the sample mean, $\mu$ is the value tested at the null hypothesis, $\sigma$ is the standard deviation and n is the size of the sample.

0.7 is tested at the null hypothesis:

This means that $\mu = 0.7, \sigma = \sqrt{0.7*0.3}$

The sociologist found that 375 of the 500 travelers randomly selected and interviewed indicated that the airports were safe.

This means that $n = 500, X = \frac{375}{500} = 0.75$

Value of the z-statistic:

$z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}$

$z = \frac{0.75 - 0.7}{\frac{\sqrt{0.7*0.3}}{\sqrt{350}}}$

$z = 2.44$

P-value of the test:

Probability of z being larger than 2.44, that is, a proportion larger than 0.75.

This is, looking at the z-table, 1 subtracted by the pvalue of Z = 2.44. S

Z = 2.44 has a pvalue of 0.9927

1 - 0.9927 = 0.0073

0.0073 < 0.05, which means that we reject the null hypothesis and conclude that the true proportion of interest is higher than 0.7.

8 0

3 years ago

What is the minimum hot-holding temperature requirement for pizza?

Whitepunk [10]

Answer:

the hot-holding temperature threshold is 135 degrees Fahrenheit

Step-by-step explanation:

the hot-holding temperature threshold is 135 degrees Fahrenheit

7 0

3 years ago

There are 12 different cookies on a plate. Aiden will choose 3 of these cookies to pack in his lunch. How many different groups

kupik [55]

The number of different groups of cookies he can choose from the 12 cookies is 220

<h3>How to determine the number of different groups of cookies he can choose from the 12 cookies?</h3>

The given parameters are:

Number of cookies, n = 12

Selected cookies, r = 3

The number of different groups of cookies he can choose from the 12 cookies is calculated as:

Numbers = 12C3

The combination formula is represented as:

nCr = n!/(n - r)!r!

Substitute the known values in the above equation

Numbers = 12!/(12 - 3)!3!

Evaluate the difference in the above equation

Numbers = 12!/9!3!

Expand the above equation

Numbers = 12*11*10*9!/9!3!

Evaluate the quotient

Numbers = 12*11*10/3!

Expand the above equation

Numbers = 12*11*10/3*2*1

Evaluate the products

Numbers = 1320/6

Evaluate the quotients

Numbers = 220

Hence, the number of different groups of cookies he can choose from the 12 cookies is 220

So, the complete parameters are:

Number of cookies, n = 12

Selected cookies, r = 3

Number of selection = 220