Substitution:
2x + (6(1/2x - 6)) = 19
2x + 3x - 36 = 19
5x - 36 = 19
+ 36
5x = 55
÷ 5
x = 11

y = (1/2 × 11) - 6
y = 5.5 - 6
y = -0.5

Elimination:
y = 1/2x - 6
- y
0 = 1/2x - 6 - y
+ 6
1/2x - y = 6

3x - 6y = 36
2x + 6y = 19
(add)
5x = 55
÷ 5
x = 11

y = (1/2 × 11) - 6
y = 5.5 - 6
y = -0.5

I hope this helps! Let me know if you need me to explain why I did some things :)

8 0

3 years ago

You have 42 ft. of fencing (1 ft. segments) to make a rectangular garden. How much should each side be to maximize your total ar

Verizon [17]

Answer:

$Length=10.5\ ft$

$Width=10.5\ ft$

$Area=110.25\ ft^{2}$

Step-by-step explanation:

Let

x----> the length of the rectangular garden

y---> the width of the rectangular garden

we know that

The perimeter of the rectangle is equal to

$P=2(x+y)$

we have

$P=42\ ft$

$42=2(x+y)$

simplify

$21=(x+y)$

$y=21-x$ ------> equation A

Remember that the area of rectangle is equal to

$A=xy$ ----> equation B

substitute equation A in equation B

$A=x(21-x)$

$A=21x-x^{2}$ ----> this is a vertical parabola open downward

The vertex is a maximum

The y-coordinate of the vertex is the maximum area

The x-coordinate of the vertex is the length side of the rectangle that maximize the area

using a graphing tool

The vertex is the point $(10.5,110.25)$

see the attached figure

$x=10.5\ ft$

Find the value of y

$y=21-10.5=10.5\ ft$

The garden is a square

the area is equal to

$A=(10.5)(10.5)=110.25\ ft^{2}$ ----> is equal to the y-coordinate of the vertex is correct

6 0

3 years ago

Samirs bedroom has an area of 48 square feet.

vazorg [7]

Answer: 2 feet

Step-by-step explanation:

3 0

3 years ago

The distribution of a sample of the outside diameters of PVC pipes approximates a normal distribution. The mean is 14.0 inches,

lakkis [162]

Answer:

A. 13.9 and 14.1 inches

See explanation below.

Step-by-step explanation:

Previous concepts

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".

Solution to the problem

Let X the random variable that represent the outside diameters of a population, and for this case we know the distribution for X is given by:

$X \sim N(14,0.1)$

Where $\mu=14$ and $\sigma=0.1$

If we want the middle 68% of the data we need to have on the tails 16% on each one

For this part we want to find a value a, such that we satisfy this condition:

$P(X>a)=0.84$ (a)

$P(X$ (b)

Both conditions are equivalent on this case. We can use the z score again in order to find the value a.

As we can see on the figure attached the z value that satisfy the condition with 0.16 of the area on the left and 0.84 of the area on the right it's z=-0.994. On this case P(Z<-0.994)=0.16 and P(z>-0.994)=0.84

If we use condition (b) from previous we have this:

$P(X$