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Solve for x someone help please. If possible please include steps

olga55 [171]

Answer:

10

Step-by-step explanation:

(x + 2) + (-2 + x) = 20

2x + 0 = 20

2x = 20

x = 20/2

x = 10

4 0

3 years ago

Read 2 more answers

The difference of two numbers is 15. Five times the smaller is the same as 9 less than twice the larger. Find the numbers

Usimov [2.4K]

Answer:

x= -13

y= -28

Step-by-step explanation:

To find the two numbers, write a system of equations with x as one number and y as another:

x-y=15

5x=2y-9

Use substitution to substitute one equation into another. Then solve for the variable.

x=15+y into 5x=2y-9

becomes

5(15+y) = 2y-9

75+5y = 2y- 9

75+3y= -9

3y = -84

y= -28

To find x, substitute y= -28 into one equation.

x - (-28) = 15

x+28 =15

x = 15-28

x=-13

6 0

3 years ago

A day-care center has 2 baskets of dolls. One basket has 8 dolls, and the other basket has an unknown number of dolls in it. Wha

xenn [34]

Answer:

$d+8$

Step-by-step explanation:

Let d represent number of dolls in 2nd basket.

We have been given that a day-care center has 2 baskets of dolls. One basket has 8 dolls, and the other basket has an unknown number of dolls in it. We are asked to represent this situation in an expression.

The number in both baskets would be equal to dolls in 1st basket plus dolls in 2nd basket.

We can represent this information in an expression as:

$d+8$

Therefore, our required expression would be $d+8$ , where d represents number of dolls in 2nd basket.

3 0

3 years ago

Sooooooooooooo..........

Alika [10]

Answer:

You can usually just go to profile and change your email and it will change your name necasue your name comes from your email.

Hope this helps

PLease mark me as Brainliest

8 0

3 years ago

Read 2 more answers

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.