All categories

3 years ago

1-) Emily and her friends went to the park. They saw 15 robins and 9 blue jays. How many birds did they see.? 24 birds.

2 answers:

8 0

I decided to do a addition problem because based on the answer it couldn't be multiplication, subtraction, or division. Therefore, my problem would look like 15+9=24 birds in total.

Inessa [10]3 years ago

5 0

Answer:

<h2>24 birds.</h2>

Step-by-step explanation:

This problem can be solve by summing 15 robins to 8 blue jays, because all are birds, and the problem is asking the total birds they see. So, the calculation would be:

$15+9=24$ '

Therefore, they see 24 birds in total.

You might be interested in

Sam wants to buy 8 pencils and 6 pens, which cost a total of $8.50. He realizes he doesn't have enough cash and instead takes on

Diano4ka-milaya [45]

X = pencils, y = pens

8x + 6y = 8.50
4x + 4y = 5.....multiply by -2
----------------
8x + 6y = 8.50
-8x - 8y = -10 (result of multiplying by -2)
-----------------add
-2y = - 1.50
y = -1.50 / -2
y = 0.75 <=== pens cost 0.75

4x + 4y = 5
4x + 4(0.75) = 5
4x + 3 = 5
4x = 5 - 3
4x = 2
x = 2/4
x = 0.50 <== pencils cost 0.50

8 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

A student expanded an expression, as shown. Is the student's work correct? Explain why or why not.

alex41 [277]

The work is incorrect.

(-6) multiplies both terms inside parentheses. For some reason, the student changed the sign of that multiplier for the second term. The second term of the result should have a positive sign, the result of multiplying (-6)(-2/13) = +12/13.

4 0

3 years ago

Read 2 more answers

Math help please & explain how to dobit

Dmitrij [34]

1 1/3 you have to divide 4÷3 and u get 1 as a whole number then you get the remainder and put it as a fraction

6 0

3 years ago

Determine whether the system of linear equations has one and only one solution, infinitely many solutions, or no solution. 2x −

zloy xaker [14]

Answer:

Only one solution
(x, y) = (-0.8, -3.6)

Step-by-step explanation:

You know there is only one solution because the ratio of x- and y-coefficients is different in the two equations. That means the lines will have different slopes, so must intersect in exactly one point.

The y-coefficients are opposites, so you can eliminate the y-variable by adding the equations:

(2x -y) + (3x +y) = (2) + (-6)

5x = -4

x = -4/5 = -0.8

Substituting this into the second equation, we have ...

3(-0.8) +y = -6

y = -3.6 . . . . . . . add 2.4 to both sides

The solution is (x, y) = (-0.8, -3.6).

You can also find the solution by graphing (or using a graphing calculator).

5 0

3 years ago