All categories

3 years ago

Which One Doesn't Belong? Which expression does not belong with the others? Explain your reasoning.

Mathematics

1 answer:

Gwar [14]3 years ago

8 0

The expression that does not belong to the other group of expression is (c) 7(-2)(-5)

<h3>What are expressions?</h3>

Expressions are mathematical statements that are represented by numbers and/or variables

The expressions are given as:

5(−3)(−1)
(−4)2(−6)(−2)
7(−2)(5)
−20(−6)

Start by evaluating all 4 expressions

$5(-3)(-1) = 15$

$(-4)^2(-6)(-2) =192$

$7(-2)(5) = -70$

$-20(-6) = 120$

Notice that three of the expressions return a positive result, while one of them return a negative result

The negative expression is the odd one among the four expressions

Hence, the expression that does not belong is (c) 7(-2)(-5)

Read more about algebraic expressions at:

brainly.com/question/4344214

You might be interested in

A grocery store sells bananas for dollars a pound and grapes for dollars a pound. Devren buys 3 pounds of bananas and 4 pounds o

RoseWind [281]

Step-by-step explanation:

Let the price of each pounds of bananas be x andthe price of each pounds of grapes be y.

ATQ,

3x+4y = 10.25 ...(1)

2x+2y = 5.5 ..(2)

Multiply equation (2) by 2.

4x+4y = 11 ...(3)

Now, subtract equation (1) from (3).

4x+4y-(3x+4y) = 11-10.25

4x+4y-3x-4y = 0.75

x = 0.75

Put the value of x in equation (2)

2(0.75)+2y = 5.5

1.5+2y = 5.5

2y = 5.5 - 1.5

2y = 4

y = 2

So, there are 0.75 pounds of bananas and 2 pounds of grapes.

3 0

3 years ago

Suppose the method of tree ring dating gave the following dates A.D. for an archaeological excavation site. Please show your wor

natita [175]

Answer:

a) $\bar X=\frac{1245+1245+1321+1191+1295+1330+1239+1250+1228}{9}= 1260.444$

b) $s =\sqrt{\frac{\sum_{i=1}^n (X_i -\bar X)^2}{n-1}}$

And if we replace we got:

$s = 45.580$

c) For this case since the sampel size is n=9 <30 we can use the t distribution in order to find the confidence interval.

d) $1260.444-2.306 \frac{45.580}{\sqrt{9}}= 1225.408$

$1260.444+2.306 \frac{45.580}{\sqrt{9}}= 1295.480$

Step-by-step explanation:

For this case we ave the following data:

1245 1245 1321 1191 1295 1330 1239 1250 1228

Part a

We can calculate the sample mean with the following formula:

$\bar X = \frac{\sum_{i=1}^n X_i}{n}$

And if we replace we got:

$\bar X= \frac{1245+1245+1321+1191+1295+1330+1239+1250+1228}{9}= 1260.444$

Part b

For this case we can use the following formula in order to find the sample standard deviation:

$s =\sqrt{\frac{\sum_{i=1}^n (X_i -\bar X)^2}{n-1}}$

And if we replace we got:

$s = 45.580$

Part c

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

For this case since the sampel size is n=9 <30 we can use the t distribution in order to find the confidence interval.

Part d

The confidence interval for the mean is given by the following formula:

$\bar X \pm t_{\alpha/2}\frac{s}{\sqrt{n}}$ (1)

We need to find the degrees of freedom given by:

$df = n-1 = 9-1=8$

Since the Confidence is 0.95 or 95%, the value of $\alpha=1-0.95=0.05$ and $\alpha/2 =0.025$ , and we can use excel, a calculator or a table to find the critical value. The excel command would be: "=-T.INV(0.025,8)".And we see that $t_{\alpha/2}=2.306$

Now we have everything in order to replace into formula (1):

$1260.444-2.306 \frac{45.580}{\sqrt{9}}= 1225.408$

$1260.444+2.306 \frac{45.580}{\sqrt{9}}= 1295.480$

8 0

4 years ago

What is the first step when solving the equation below for x?

JulsSmile [24]

Answer:The x has to be alone meaning it has to be before or after the equation to solve, what you to do one side of the equation you will always do to the other side.

Step-by-step explanation:

4 0

3 years ago

Write/Indicate the corresponding measures of 300- 600-900 right triangle.

andreev551 [17]

I used a triangle generator, see picture attached

4 0

2 years ago

How do I know when a slope declines or ascends?

babunello [35]

How to tell when a slope declines or ascends is to see if the line has a positive slope (i.e. m > 0), then y always increases when x increases and y always decreases when x decreases. Thus, the graph of the line starts at the botto left and goes towards the top right.

Answer: If the line is a positive slope, y increases when x increases too. So the line on the graph starts at the bottom left and goes towards the top right ( than it's positive)

live

7 0

4 years ago