2x^2+7x+4 do not have answer ?

<img src="https://tex.z-dn.net/?f=x%20%2B%20y%20%20%3D%2014%5C%5C%202x%20%2B%204y%20%3D%2018" id="TexFormula1" title="x + y = 1

alexgriva [62]

Answer:

x = 19, y = -5

Step-by-step explanation:

x + y = 14 => x= 14-y

2x + 4y = 18 => 2(x+2y)=18 => x+2y=9

x+2y=9 => (14 - y) + 2y = 9

14 + y = 9 => y = -5

x + (-5) = 14 => x=19

5 0

3 years ago

The school uses between 300 and 400 sheets of paper per school day. If paper costs the school $2.00 per 100 sheets, approximatel

Nady [450]

Answer:

Option A. $140.00

Explanation:

1. Using the minimun number of sheets of paper in the interval [300, 400]

a) Cost: $ 2.00 / 100 sheets

b) 300 sheets / day × $ 2.00 / 100 sheets = $ 6.00 / day

c) Approimately 20 school days per month:

$ 6.00 / day × 20 day = $ 120.00

2. Using the maximum number of sheets of paper in the interval [300, 400]

a) Cost: $ 2.00 / 100 sheets

b) 400 sheets / day × $ 2.00 / 100 sheets = $ 8.00 / day

c) Approimately 20 school days per month:

$8.00 / day × 20 day = $ 160.00

3. Middle value:

Calculate the middle value between $160.00 and $120.00

[$120.00 + $160.00] / 2 = $140.00

Thus, the answer is the option A.

7 0

3 years ago

Of the entering class at a college, % attended public high school, % attended private high school, and % were home schoole

Veronika [31]

Answer:

(a) The probability that the student made the Dean's list is 0.1655.

(b) The probability that the student came from a private high school, given that the student made the Dean's list is 0.2411.

(c) The probability that the student was not home schooled, given that the student did not make the Dean's list is 0.9185.

Step-by-step explanation:

The complete question is:

Of the entering class at a college, 71% attended public high school, 21% attended private high school, and 8% were home schooled. Of those who attended public high school, 16% made the Dean's list, 19% of those who attended private high school made the Dean's list, and 15% of those who were home schooled made the Dean's list.

a) Find the probability that the student made the Dean's list.

b) Find the probability that the student came from a private high school, given that the student made the Dean's list.

c) Find the probability that the student was not home schooled, given that the student did not make the Dean's list.

Solution:

Denote the events as follows:

A = a student attended public high school

B = a student attended private high school

C = a student was home schooled

D = a student made the Dean's list

The provided information is as follows:

P (A) = 0.71

P (B) = 0.21

P (C) = 0.08

P (D|A) = 0.16

P (D|B) = 0.19

P (D|C) = 0.15

(a)

The law of total probability states that:

$P(X)=\sum\limits_{i} P(X|Y_{i})\cdot P(Y_{i})$

Compute the probability that the student made the Dean's list as follows:

$P(D)=P(D|A)P(A)+P(D|B)P(B)+P(D|C)P(C)$

$=(0.16\times 0.71)+(0.19\times 0.21)+(0.15\times 0.08)\\=0.1136+0.0399+0.012\\=0.1655$

Thus, the probability that the student made the Dean's list is 0.1655.

(b)

Compute the probability that the student came from a private high school, given that the student made the Dean's list as follows:

$P(B|D)=\frac{P(D|B)P(B)}{P(D)}$

$=\frac{0.21\times 0.19}{0.1655}\\\\=0.2410876\\\\\approx 0.2411$

Thus, the probability that the student came from a private high school, given that the student made the Dean's list is 0.2411.

(c)

Compute the probability that the student was not home schooled, given that the student did not make the Dean's list as follows:

$P(C^{c}|D^{c})=1-P(C|D^{c})$

$=1-\frac{P(D^{c}|C)P(C)}{P(D^{c})}\\\\=1-\frac{(1-P(D|C))\times P(C)}{1-P(D)}\\\\=1-\frac{(1-0.15)\times 0.08}{(1-0.1655)}\\\\=1-0.0815\\\\=0.9185$

Thus, the probability that the student was not home schooled, given that the student did not make the Dean's list is 0.9185.

3 0

2 years ago

31 - 8a = 5 ( - 4 - 5a )

timama [110]

Answer:

Step-by-step explanation:

$31 - 8a = 5(-4 - 5a)$

First, on the right-hand side of the equation, let's distribute the $5$ to each term in the parenthesis:

$31 - 8a = -20 - 25a$

Now, let's move all the terms with an $a$ to the left-hand side, and everything else to the right-hand side of the equation:

$-8a + 25a = -20 - 31$

Let's combine like terms:

$17a = -51$

Finally, let's divide each side by $17$ to get $a$ by itself on the left-hand side of the equation:

$a = -3$

4 0

3 years ago

How do you find a inverse of a equation

zmey [24]

It is opposite of what the equation is saying. Like if you had to add you would subtract or if you multiply you would divide.

3 0

3 years ago

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2x^2+7x+4 do not have answer ?​

2x^2+7x+4 do not have answer ?