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3 years ago

Given two functions f(x)=2x+4 and g(x)=−1/5x−3 , what is the function rule for (f+g)(x) ?

Mathematics

1 answer:

Angelina_Jolie [31]3 years ago

5 0

The definition is pretty simple:

$(f+g)(x) = f(x)+g(x)$

So, we only have to sum the expressions:

$f(x)+g(x) = 2x+4 - \dfrac{1}{5}x-3 = \dfrac{9}{5}x+1$

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HELP DUE IN 10 MINS!

Scilla [17]

Answer:

$\checkmark \text{B. The area of the circle is } 729\pi,\\\checkmark \text{D. The arc length of the sector is } 12\pi$

Step-by-step explanation:

Area of a circle with radius $r$ : $r^2\pi$

Circumference of a sector with radius $r$ : $2r\pi$

Area of sector with angle $\theta$ : $r^2\pi\cdot \frac{\theta}{360}$ .

Arc length of sector with angle $\theta$ : $2r\pi\cdot \frac{\theta}{360}$

Using these equations, we get the following information:

Area of circle: $27^2\pi=729\pi$

Circumference of a circle: $2\cdot 27\cdot \pi=54\pi$

Area of sector: $27^2\pi\cdot \frac{80}{360}=162\pi$

Arc length of sector: $2\cdot 27\cdot \pi \cdot \frac{80}{360}=12\pi$

3 0

2 years ago

What do you round 150 to??

Vedmedyk [2.9K]

It depends on what you are rounding off to.

If you are round it off to the nearest ten, you must look at the unit number.
If you are rounding off to the nearest hundred, you must look at the ten number.

In this case I think they are asking to round to the nearest hundred. Now we must look at the ten number, which is the number after the 'hundred' number.

The ten number is '5' and the hundred number is '1'. If the ten number is 5 or above, it changes to 0 and it makes the hundred number one higher.

So because the ten number is 5, it changes to 0 and it makes the hundred number one higher, to become 2.

The number is now 200.

5 0

3 years ago

Lee drove 420 miles and used 15 gallons pf gasoline.How many miles did Lee's car travel per gallon of gasoline?

kondor19780726 [428]

Divide the two numbers. The equation is 420/15=28. So Lee would get 28 miles per gallon of gasoline. I hope this helps!

3 0

3 years ago

A fair coin is to be tossed 20 times. Find the probability that 10 of the tosses will fall heads and 10 will fall tails, (a) usi

lbvjy [14]

Using the distributions, it is found that there is a:

a) 0.1762 = 17.62% probability that 10 of the tosses will fall heads and 10 will fall tails.

b) 0% probability that 10 of the tosses will fall heads and 10 will fall tails.

c) 0.1742 = 17.42% probability that 10 of the tosses will fall heads and 10 will fall tails.

Item a:

Binomial probability distribution

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$C_{n,x} = \frac{n!}{x!(n-x)!}$

The parameters are:

x is the number of successes.
n is the number of trials.
p is the probability of a success on a single trial.

In this problem:

20 tosses, hence $n = 20$ .
Fair coin, hence $p = 0.5$ .

The probability is P(X = 10), thus:

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 10) = C_{20,10}.(0.5)^{10}.(0.5)^{10} = 0.1762$

0.1762 = 17.62% probability that 10 of the tosses will fall heads and 10 will fall tails.

Item b:

In a normal distribution with mean $\mu$ and standard deviation $\sigma$ , the z-score of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

It measures how many standard deviations the measure is from the mean.
After finding the z-score, we look at the z-score table and find the p-value associated with this z-score, which is the percentile of X.
The binomial distribution is the probability of x successes on n trials, with p probability of a success on each trial. It can be approximated to the normal distribution with $\mu = np, \sigma = \sqrt{np(1-p)}$ .

The probability of an exact value is 0, hence 0% probability that 10 of the tosses will fall heads and 10 will fall tails.

Item c:

For the approximation, the mean and the standard deviation are:

$\mu = np = 20(0.5) = 10$

$\sigma = \sqrt{np(1 - p)} = \sqrt{20(0.5)(0.5)} = \sqrt{5}$

Using continuity correction, this probability is $P(10 - 0.5 \leq X \leq 10 + 0.5) = P(9.5 \leq X \leq 10.5)$ , which is the p-value of Z when X = 10.5 subtracted by the p-value of Z when X = 9.5.