Sarah and amanda each have 2 bags with 4 marbles in each .how many marbles do they have altogether?

Answer please! I have been "getting" the correct answer, as far as I know. The answer which I got was 10x^2 - 4x. But I don't se

GarryVolchara [31]

Answer:

The answer is 10x² - 4x.

Step-by-step explanation:

You have to apply Distributive Law,

$a(m + n) = am + an$

So for this question :

$2x(5x - 2)$

$= 2x(5x) + 2x( - 2)$

$= 10 {x}^{2} - 4x$

4 0

2 years ago

micheal pays 30 to enter a state fair, plus 4 for each ride. which of the following equations represent his total cost

Shkiper50 [21]

Answer:

I cant see the equation but it should go something along the lines of t = 30 + 4r

Step-by-step explanation:

t = total

r = number of rides

Example: If he went on 4 rides, hen u would imput 4 into r like this

t = 30 + 4 (4)

t = 30 + 16

t = 46

8 0

2 years ago

An instructor in a college class recently gave an exam that was worth a total of 100 points. The instructor inadvertently made t

solniwko [45]

Answer:

B) Method 2 will increase the standard deviation of the students' scores.

Step-by-step explanation:

Given that an instructor in a college class recently gave an exam that was worth a total of 100 points.

The average score for his students was 43 and the standard deviation of the scores was 5 points.

And now he is considering two different strategies for rescaling the exam results of which:

Method 1 = Add 17 points to everyone's score.

Method 2 = Multiply everyone's score by 1.7 .

And we have to check what will be the impact of these methods on the standard deviation of the students' scores.

For this let us consider a simple example to understand this:

Firstly, Formula for calculating Standard Deviation = $\sqrt{\frac{\sum (X-Xbar)^{2}}{n-1}}$

Suppose,

X X - Xbar $(X - Xbar)^{2}$

3 3 - 6 = -3 -3 * -3 = 9

5 5 - 6 = -1 -1 * -1 = 1

10 10 - 6 = 4 4 * 4 = 16

Mean of above data, Xbar = $\frac{3+ 5+10}{3}$ = 6

Standard Deviation of data = $\sqrt{\frac{26}{3-1} }$ = 3.6055

Now let us suppose that we multiply each value of above data with 2 so the new data will be:

X X - Xbar $(X - Xbar)^{2}$

3*2 = 6 6 - 12 = -6 -6 * -6 = 36

5*2 = 10 10 - 12 = -2 -2 * -2 = 4

10*2 =20 20 - 12 = 8 8 * 8 = 64

Mean of new data, Xbar = $\frac{6+ 10+20}{3}$ = 12

Standard Deviation of new data = $\sqrt{\frac{104}{3-1} }$ = 7.2111

Hence, we see that when we multiply any value to the data the standard deviation will increase and in other words it will multiplied by that value which value we multiplied with each data value i.e. when we multiply each data value with 2 the standard deviation also get multiplied by as

3.6055 * 2 = 7.2111

Therefore option B is correct that Method 2 will increase the standard deviation of the students' scores.

And on the other hand Similarly by adding any constant to the data the Standard Deviation will remain same. Therefore Method 1 will have no impact on standard deviation of the students' scores.

8 0

2 years ago

Given the formula K = LMN, what is the formula for M?

Andre45 [30]

To start off devide both sides by M i.e
K/M=LMN/M
-> K/M=LN
Then devide by K to remove it on the left , this will end you up with M=LN/K
So the answer is (c).
Hope this helps :).

5 0

2 years ago

When factored completely, the expression p^4-81 is equivalent to what?

Mice21 [21]

Differnce of 2 pefect squares
a^2-b^2=(a-b)(a+b)
(p^2)^2-9^2=(p^2-9)(p^2+9)

p^2-9=(p-3)(p+3)

factored is
(p-3)(p+3)(p^2+9)

4 0

2 years ago

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