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3 years ago

Whats the answer and work for this problem (3)

Mathematics

1 answer:

mamaluj [8]3 years ago

3 0

This is a system of equations. You can solve it by substitution or elimination. I'm going to use substitution x - 2y = -4.5; add 2y to each side x - 2y + 2y = -4.5 + 2y; simplify x = 2y - 4.5 2(2y - 4.5) + 3y = 12 4y - 9 + 3y = 12 7y - 9 = 12 7y - 9 + 9 = 12 + 9 7y = 21 y = 3 <--------first answer x - 2y = -4.5 x - 2(3) = -4.5 x - 6 = -4.5 x -6 + 6 = -4.5 + 6 x = 1.5 <--------second answer Check: 2(1.5) + 3(3) = 12? 3 + 9 = 12? 12 = 12; It checks 1.5 - 2(3) = -4.5? 1.5 - 6 = -4.5? -4.5 = -4.5; It checks x = 1.5 and y = 3 <-----------Final Answer

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Help me please<br> How many solutions does the equation<br> x -4 = 12 - 2x have? Explain.<br> - ? .

MA_775_DIABLO [31]

Answer: <em>one solution.</em>

Step-by-step explanation:

$\dfrac{2}{3} x-4=12-2x\\\\\dfrac{2}{3} x+2x=12+4\\\\2\dfrac{2}{3} x=16\\\\\dfrac{8}{3} x=16\\\\8x=16 \cdot 3\\\\8x=48\\\\x=\dfrac{48}{8} =6$

<em>This equation has one solution: x = 6.</em>

8 0

3 years ago

In 2006, 95% of new cars in the US came with a spare tire. In 2017, 72% came with a spare tire.

MArishka [77]

Using the Central Limit Theorem, it is found that:

The mean is 0.23.

The standard deviation is $s = \sqrt{\frac{0.95(0.05)}{250} + \frac{0.72(0.28)}{250}}$ .

<h3>Central Limit Theorem</h3>

It states that for a <u>proportion p in a sample of size n</u>, the sampling distribution of sample proportions has mean $p$ and standard deviation $s = \sqrt{\frac{p(1 - p)}{n}}$

When two variables are subtracted, the mean is the subtraction of the means, while the standard deviation is the square root of the sum of the variances.

In 2006, 95% of new cars in the US came with a spare tire, with a sample of 250, hence:

$p_1 = 0.95, s_1 = \sqrt{\frac{0.95(0.05)}{250}}$

In 2017, 72% of new cars in the US came with a spare tire, with a sample of 250, hence:

$p_2 = 0.72, s_2 = \sqrt{\frac{0.72(0.28)}{250}}$

Hence, for the distribution of differences:

$p = p_1 - p_2 = 0.95 - 0.72 = 0.23$

$s = \sqrt{s_1^2 + s_2^2} = \sqrt{\frac{0.95(0.05)}{250} + \frac{0.72(0.28)}{250}}$

To learn more about the Central Limit Theorem, you can take a look at brainly.com/question/16695444

7 0

2 years ago

Find the roots of y= -3^2 - 5x +1

Reil [10]

Answer:

The right answer is the second

Step-by-step explanation:

D=b^2-4ac

D=25+12

D=37

7 0

3 years ago

principle is used to find the number of strings of eight uppercase English letters that start or end with the letters BO (in tha

yKpoI14uk [10]

There are 6 other positions in the string, each with 26 choices. So if you fix BO as the first two letters, there are $26^6$ possible strings that you can make.

If BO is at the end of the string, you still have $26^6$ possible strings.

Together, then, you have $2\times26^6$ possible strings.

5 0

3 years ago

Suppose an investment of $5,000 doubles every 12 years. How much is the investment worth after 36 years? After 48 years?

nadezda [96]

This can be done without exponential equations.

It doubles every 12 years so it has doubled in price
5,000 * 2 = 10,000

After 36 years the value has increased 8 times
5,000 * 8 = 40,000

After 48 years the value has increased 16 times
5,000 * 16 = 80,000

8 0

3 years ago