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natali 33 [55]
4 years ago
9

Describe and correct the error made in solving the system of equations by elimination

Mathematics
1 answer:
lesya692 [45]4 years ago
6 0
The mistake was when she multiplied the 2nd equation by 5, she forgot to also multiply that last number 10 by 5 as well.

correction :
5x + 3y - z = 15
-x + 2y + 3z = 10...multiply by 5
---------------------
5x + 3y - z = 15
-5x + 10y + 15z = 50 (result of multiplying by 5)
--------------------add
13y + 14z = 65

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Consider that the roots of a cubic equation with integral coefficients are 1, −2, and 3.
Iteru [2.4K]

Answer:

The answer is option A) X + 2

Step-by-step explanation:

Any polynomial of order n can be expressed in terms of their roots in factors of the form

(x-a)(x-b)(x-c)(x-d)....... = 0

Where a,b,c,d,... are the roots of the polynomial

In the example shown

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

And -2 happens to be the root of the polynomial in question

3 0
3 years ago
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The question is attached<br> perimeter
ycow [4]

Answer:

62 cm

Step-by-step explanation:

48/4 = 12 so 1 side = 12

the base of the triangle therefore must also be 12 so 38 - 12 = 26

26 + 36 = 62

(2 sides of triangle + 3 sides of square)

4 0
3 years ago
The following data represent the number of people aged 25 to 64 years covered by health insurance​ (private or​ government) in 2
Yuri [45]

The mean age is equal to: 44.09.

The standard deviation is equal to: 10.07.

<h3>How to determine the mean age and standard deviation?</h3>

First of all, we would determine the median of each class interval as follows:

Median 1 = (25 + 34)/2 = 29.5

Median 2 = (35 + 44)/2 = 39.5

Median 1 = (45 + 54)/2 = 49.5

Median 1 = (55 + 64)/2 = 59.5

Next, we would calculate the mean age by using this mathematical expression:

Mean age = ∑fx/∑f

Substituting the given parameters into the formula, we have;

Mean age = [(24.3 × 29.5) + (36.1 × 39.5) + (36.7 × 49.5) + (20.9 × 59.5)]/(24.3 + 36.1 + 36.7 + 20.9)

Mean age = [716.85 + 1,425.95 + 1,816.65 + 1,243.55]/118

Mean age = [5,203]/118

Mean age = 44.09.

Now, we can calculate the standard deviation as follows:

Standard deviation, S = √((∑f(xi - μ)²/∑f)

Standard deviation, S = √((24.3 × (29.5 - 44.09)² + (36.1 × (39.5 - 44.09)² + (36.7 × (49.5 - 44.09)² + (20.9 × (59.5 - 44.09)²)/(24.3 + 36.1 + 36.7 + 20.9))

Standard deviation, S = √((5172.70 + 760.56 + 1,074.14 + 4,963.08)/118)

Standard deviation, S = √(11,970.48/118)

Standard deviation, S = √101.5

Standard deviation, S = 10.07.

Read more on standard deviation here: brainly.com/question/14676082

#SPJ1

6 0
1 year ago
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saw5 [17]

Answer:

the answer is a. scales triangle

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3 0
4 years ago
5.<br> Factorise each of the following.<br> (a)-15ab-6ab² <br> (b) 6x(2y-5)-3(5-2y)
Kobotan [32]
(a).
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= -(15ab+6ab^2)
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(b).
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= 6x(2y-5)+3(2y-5)
= (6x+3)(2y-5)
= 3(2x+1)(2y-5)

Tip: If you want to check your answer for (a), you can always simplify it back and see whether it is same as the question.

Hope this helps : )
7 0
2 years ago
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