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3 years ago

What is the solution to the system of equations of linear equations 2x + 4y = 38 and 10x + 3y = 105

1 answer:

6 0

A) 2x + 4y = 38
B) 10x + 3y = 105
Multiplying A) by -5
A) -10x -20y = -190 then adding it to B)
B) 10x + 3y = 105

-17y = -85
y = 5
x = 9

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Solve the following systems by Elimination

Alenkasestr [34]

Answer:

The solutions for both system of equations are as follows:

(5,2)
(2,-1)

Step-by-step explanation:

The first set of equations is:

$4x+6y=32\\3x-6y=3\\$

It can clearly be seen that the coefficients of y are already same in magnitude with different signs so we have to add both equations

So adding both equations, we get

$4x+6y+3x-6y = 32+3\\7x = 35\\\frac{7x}{7} = \frac{35}{7}\\x = 5$

Putting x=5 in equation 1

$4(5)+6y = 32\\20+6y = 32\\6y = 32-20\\6y = 12\\\frac{6y}{6} = \frac{12}{6}\\y = 2$

The solution is (5,2)

The second set of simultaneous equations is:

$-3x+5y=-113x+7y=-1$

We can see that the coefficients of x in both equations are same in magnitude with opposite signs so

Adding both equations

$-3x+5y+3x+7y = -11-1\\12y = -12\\\frac{12y}{12} = \frac{-12}{12}\\y = -1$

Putting y= -1 in first equation

$-3x+5(-1)=-11\\-3x-5=-11\\-3x=-11+5\\-3x=-6\\\frac{-3x}{-3} = \frac{-6}{-3}\\x = 2$

The solution is: (2,-1)

Hence,

The solutions for both system of equations are as follows:

(5,2)
(2,-1)

3 0

3 years ago

Abigail bought some mangoes at 3 for GH¢ 0.90 and sold all at 4 for GH¢ 1.60.If she made a profit of GH¢ 35.00,how many mangoes

umka21 [38]

Answer:

Step-by-step explanation:

Total costs = 4 + (3 * 2) + 5 + 15

Total costs = 4 + 6 + 5 + 15

Total costs = $ 30

Substituting values we have:

Total change = 32 - 30

Total change = 2 $

6 0

3 years ago

Which is a characteristic of a studio apartment?

GenaCL600 [577]

Answer:d

its a apartment thats just one big room

8 0

3 years ago

Test scores of the student in a school are normally distributed mean 85 standard deviation 3 points. What's the probability that

Mrrafil [7]

Answer:

The probability that a random selected student score is greater than 76 is $\\ P(x>76) = 0.99865$ .

Step-by-step explanation:

The Normally distributed data are described by the normal distribution. This distribution is determined by two parameters, the population mean $\\ \mu$ and the population standard deviation $\\ \sigma$ .

To determine probabilities for the normal distribution, we can use the standard normal distribution, whose parameters' values are $\\ \mu = 0$ and $\\ \sigma = 1$ . However, we need to "transform" the raw score, in this case x = 76, to a z-score. To achieve this we use the next formula:

$\\ z = \frac{x - \mu}{\sigma}$ [1]

And for the latter, we have all the required information to obtain z. With this, we obtain a value that represent the distance from the population mean in standard deviations units.

<h3>The probability that a randomly selected student score is greater than 76</h3>

To obtain this probability, we can proceed as follows:

First: obtain the z-score for the raw score x = 76.

We know that:

$\\ \mu = 85$

$\\ \sigma = 3$

$\\ x = 76$

From equation [1], we have:

$\\ z = \frac{76 - 85}{3}$

Then

$\\ z = \frac{-9}{3}$

$\\ z = -3$

Second: Interpretation of the previous result.

In this case, the value is three (3) standard deviations below the population mean. In other words, the standard value for x = 76 is z = -3. So, we need to find P(x>76) or P(x>-3).

With this value of $\\ z = -3$ , we can obtain this probability consulting the cumulative standard normal distribution, available in any Statistics book or on the internet.

Third: Determination of the probability P(x>76) or P(x>-3).

Most of the time, the values for the cumulative standard normal distribution are for positive values of z. Fortunately, since the normal distributions are symmetrical, we can find the probability of a negative z having into account that (for this case):

$\\ P(z>-3) = 1 - P(z>3) = P(z$

Then

Consulting a cumulative standard normal table, we have that the cumulative probability for a value below than three (3) standard deviations is:

$\\ P(z$

Thus, "the probability that a random selected student score is greater than 76" for this case (that is, $\\ \mu = 85$ and $\\ \sigma = 3$ ) is $\\ P(x>76) = P(z>-3) = P(z$ .