2,1 reflected over the x axis?<br> HELP PLEASEEE...

AVprozaik [17]

Answer:

$x+ y = 10 ---(1)\\ x\cdot y = 9 ---(2)\\\\from(2) \ y = \frac{9}{x}\\\\substitute \ y \ in (1) \\x + \frac{9}{x} = 10\\\\x^2 + 9 - 10x = 0\\x^2 -10x + 9 = 0\\x^2 -9x -x +9 = 0\\x(x-9)-1(x-9)=0\\(x-1)(x-9)=0\\x = 1 \ or \ 9\\$

substitute x in y = 9/x

=> y = 9 or 1

So the number are 1 and 9 or 9 and 1

6 0

3 years ago

2. Suppose that a particular medical procedure has a cost that is approximately normally distributed with a mean of $19,800 and

Lina20 [59]

Answer:

a) 0.5085

b) -1.6551

c) 0.8103834

Step-by-step explanation:

Data provided in the question:

Mean = $19,800

Standard deviation, s = $2,900

Now,

z score = [ X - Mean ] ÷ s

a) The procedure costs between $18,000 and $22,000

For X = $22,000

z-score = [ $22,000 - $19,800 ] ÷ $2,900

= 0.7586

For X = $18,000

z-score = [ $18,000 - $19,800 ] ÷ $2,900

= -0.62069

P(procedure costs between $18,000 and $22,000)

= P(z < 0.7586) - P( z < -0.62069)

= 0.7759541 - 0.2674018 [ P value from standard z table ]

= 0.5085

b) The procedure costs less than $15,000

For X = $15,000

z-score = [ $15,000 - $19,800 ] ÷ $2,900

= -1.6551

thus,

The procedure costs less than $15,000

P (z < -1.655172 )

= 0.0489448 [ P value from standard z table ]

c) The procedure costs more than $17,250

z-score = [ $17,250 - $19,800 ] ÷ $2,900

= -0.87931

thus,

The procedure costs more than $17,250.

P (z > -0.87931 ) = 0.8103834

4 0

3 years ago

I need this tomorrow but take your time.

Scrat [10]

Answer:

J

Step-by-step explanation:

7 0

3 years ago

Read 2 more answers

Find the reduced row echelon form of the following matrices and then give the solution to the system that is represented by the

GaryK [48]

Answer:

a)

Reduced Row Echelon:

$\left[\begin{array}{cccc}1&1/2&0&0\\0&1&7/4&0\\0&0&1&-4\end{array}\right]$

Solution to the system:

$x_3=-4\\x_2=-\frac{7}{4}x_3=7\\x_1=-\frac{1}{2}x_2=-\frac{7}{2}$

b)

Reduced Row Echelon:

$\left[\begin{array}{cccc}4&3&0&7\\0&0&2&-17\\0&0&2&-17\end{array}\right]$

Solution to the system:

$x_3=-\frac{17}{2}\\x_1=\frac{7-3x_2}{4}$

x_2 is a free variable, meaning that it has infinite possibilities and therefore the system has infinite number of solutions.

Step-by-step explanation:

To find the reduced row echelon form of the matrices, let's use the Gaussian-Jordan elimination process, which consists of taking the matrix and performing a series of row operations. For notation, R_i will be the transformed column, and r_i the unchanged one.

a) $\left[\begin{array}{cccc}0&4&7&0\\2&1&0&0\\0&3&1&-4\end{array}\right]$