All categories

2 years ago

Josh is trying to factor the expression

Mathematics

1 answer:

mrs_skeptik [129]2 years ago

4 0

Answer:

a) Josh likely made the negative and positive multiplication error.

b) -20a-8+12b

= -4(5a+2-3b)

Step-by-step explanation:

To check if you are correct, you can always simplify it again:

-4(5a+2-3b)

=-20a-8+12b

Remember:

Negative times negative equals to positive, negative times positive equals to negative!

I hope this is helpful! :)

You might be interested in

671 ÷24showing work please and thank you

telo118 [61]

Answer: 27.958333333333333333333333333333........

Step-by-step explanation: Use long division method or do rounding method round each number and divide.

6 0

2 years ago

Read 2 more answers

A data mining routine has been applied to a transaction dataset and has classified 88 records as fraudulent (30 correctly so) an

chubhunter [2.5K]

Answer:

The classification matrix is attached below

Part a

The classification error rate for the records those are truly fraudulent is 65.91%.

Part b

The classification error rate for records that are truly non-fraudulent is 96.64%

Step-by-step explanation:

The classification matrix is obtained as shown below:

The transaction dataset has 30 fraudulent correctly classified records out of 88 records, that is, 30 records are correctly predicted given that an instance is negative.

Also, there would be 88 - 30 = 58 non-fraudulent incorrectly classified records, that is, 58 records are incorrectly predicted given that an instance is positive.

The transaction dataset has 920 non-fraudulent correctly classified records out of 952 records, that is, 920 records are correctly predicted given that an instance is positive.

Also, there would be 952 - 920 = 32 fraudulent incorrectly classified records, that is, 32 records incorrectly predicted given that an instance is negative.

That is,

Predicted value

Active value Fraudulent Non-fraudulent

Fraudlent 30 58

non-fraudulent 32 920

The classification matrix is obtained by using the information related to the transaction data, which is classified into fraudulent records and non-fraudulent records.

The error rate is obtained as shown below:

The error rate is obtained by taking the ratio of $\left( {b + c} \right)(b+c)$ and the total number of records.

The classification matrix is, shown above

The total number of records is, $30 + 58 + 32 + 920 = 1,040$

The error rate is,

$\begin{array}{c}\\{\rm{Error}}\,{\rm{rate}} = \frac{{b + c}}{{{\rm{Total}}}}\\\\ = \frac{{58 + 32}}{{1,040}}\\\\ = \frac{{90}}{{1,040}}\\\\ = 0.0865\\\end{array}$

The percentage is $0.0865 \times 100 = 8.65$

(a)

The classification error rate for the records those are truly fraudulent is obtained by taking the rate ratio of b and $\left( {a + b} \right)(a+b)$ .

The classification error rate for the records those are truly fraudulent is obtained as shown below:

The classification matrix is, shown above and in the attachment

The error rate for truly fraudulent is,

$\begin{array}{c}\\FP = \frac{b}{{a + b}}\\\\ = \frac{{58}}{{30 + 58}}\\\\ = \frac{{58}}{{88}}\\\\ = 0.6591\\\end{array}$

The percentage is, $0.6591 \times 100 = 65.91$

(b)

The classification error rate for records that are truly non-fraudulent is obtained by taking the ratio of d and $\left( {c + d} \right)(c+d)$ .

The classification error rate for records that are truly non-fraudulent is obtained as shown below:

The classification matrix is, shown in the attachment

The error rate for truly non-fraudulent is,

$\begin{array}{c}\\TP = \frac{d}{{c + d}}\\\\ = \frac{{920}}{{32 + 920}}\\\\ = \frac{{920}}{{952}}\\\\ = 0.9664\\\end{array}$

The percentage is, $0.9664 \times 100 = 96.64$

8 0

2 years ago

5 squirrels were found to have an average weight of 8.9 ounces with a sample standard deviation is 0.9. Find the 95% confidence

stira [4]

Answer: ( 8.11 , 9.69)

the 95% confidence interval of the true mean weight

= ( 8.11 , 9.69)

Step-by-step explanation:

Confidence interval can be defined as a range of values so defined that there is a specified probability that the value of a parameter lies within it.

The confidence interval of a statistical data can be written as.

x+/-zr/√n

Given that;

Mean x = 8.9

Standard deviation r = 0.9

Number of samples n = 5

Confidence interval = 95%

z(at 95% confidence) = 1.96

Substituting the values we have;

8.9+/-1.96(0.9/√5)

8.9+/-1.96(0.4025)

8.9+/- 0.79

= ( 8.11 , 9.69)

Therefore at 95% confidence interval (a,b) = ( 8.11 , 9.69)

7 0

3 years ago

What is 30x-140-(x-4)

gladu [14]

30x-x-144 might get you closer

6 0

2 years ago

Read 2 more answers

Circle P is shown. Line segment A B goes from one side of the circle to another. Line segment E F is a tangent that intersects t

Harrizon [31]

Answer:81

Step-by-step explanation:

6 0

2 years ago

Read 2 more answers