System of two linear equations can't have exactly two solutions. Reason is that when we have two straight lines,they can only intersect at one point of intersection,no more. Or let's see if lines are equivalent,then they have infinitely many solutions,because any point on line can be solution for the system.

Step-by-step explanation:

5 0

3 years ago

Find the rate of discount for a pair of pants that cost 65$ and are on sell for 39

lutik1710 [3]

Answer: 65 - $39 = $26 >> amount you save

26 / 65 = 0.4 = 40% >> discount rate

Step-by-step explanation:

6 0

3 years ago

According to a certain website, wine critics generally use a wine-scoring scale to communicate their opinions on the relative qu

const2013 [10]

Answer:

$\bar x = 82$

$\sigma = 9.64$

Step-by-step explanation:

Given

$n = 12$

$87\ 91\ 86\ 82\ 72\ 91\ 60\ 77\ 80\ 79\ 83\ 96$

Solving (a); Point estimate of mean

To do this, we simply calculate the sample mean

$\bar x = \frac{\sum x}{n}$

$\bar x = \frac{87+ 91+ 86+ 82+72+91+60+77+80+79+83+96}{12}$

$\bar x = \frac{984}{12}$

$\bar x = 82$

Solving (b); Point estimate of standard deviation

To do this, we simply calculate the sample standard deviation

$\sigma = \sqrt{\frac{\sum(x-\bar x)^2}{n - 1}$

$\sigma = \sqrt\frac{(87-82)^2+ (91-82)^2+ ....+ (79-82)^2+ (83-82)^2+ (96-82)^2}{12-1}$

$\sigma = \sqrt\frac{1022}{11}$

$\sigma = \sqrt{92.91}$

$\sigma = 9.64$

<em>Note that: The sample mean and the sample standard deviation are the best point estimators for the mean and the standard deviation, respectively.</em>

<em>Hence, the need to solve for sample mean and sample standard deviation</em>

3 0

3 years ago

Subtract (4x − 3y) from the sum of (12x + 9y) and (−2y). A) 8x + 10y B) 8x - 10y C) 8x − 7y D) −8x + 10y

labwork [276]

(12x + 9y) + (-2y) - (4x - 3y)

= 12x + 9y - 2y - 4x + 3y

= 12x - 4x + 9y - 2y + 3y

= 8x + 10y

A) 8x + 10y

3 0

3 years ago

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