Ask question

Ask question

All categories

4 years ago

14

Ms. Velez will use both x gray bricks and y red bricks to build a wall around her garden. Gray bricks cost $0.45 each and red br

icks cost $0.58 each. She can spend up to $200 on her project, and wants the number of red bricks to be less than half the number of gray bricks.
Select all inequalities that model this situation.
x≥0
0 0.45x+0.58y<200
x>0
0 0.45x+0.58y≤200
(More than one answer)

1 answer:

Finger [1]4 years ago

6 0

Let

x--------> the number of gray bricks

y--------> the number of red bricks

we know that

$y < \frac{x}{2}$ ------> inequality 1

$0.45x+0.58y \leq 200$ <em>-----> </em>inequality 2

therefore

<u>the answer is</u>

x > 0

0.45x+0.58y≤200

You might be interested in

HELP!!! 100 POINTS ANSWER FAST

Viktor [21]

Answer:

(x - 4)^2 = 9

Step-by-step explanation:

<u>Completing the square</u>

x^2 - 8x + 7 = 0
x^2 - 2*4x + 16 - 9 = 0

(x^2 - 2*4x + 4^2) = 9

(x - 4)^2 = 9

<u>The blanks are</u>

- 4 and 9

4 0

3 years ago

Read 2 more answers

Blaine buys 2 books and the total cost is $24.18. What is the constant of proportionality that relates the cost in dollars, y, t

Finger [1]

Answer:

$12.09

Step-by-step explanation:

formula Y = KX

where; y = $24.18

x = 2 books

k = constant proportionality

Step 1. Do the equation based on the data given

$24.18 = k 2

Step 2. Divide 2 on both sides to eliminate integer on the right side

$24.18 / 2 = k2/2

Answer ;

k = $12.09 dollar in relate to number of books

4 0

4 years ago

Fiona purchased 400 m2 of plastic sheeting and needs to cut it into rectangles of area 500 cm2. This can be done with no waste.

hoa [83]

Answer:

8000

Step-by-step explanation:

The number will be ...

(400 m^2)/(500 cm^2) = 0.8 (m/cm)^2 = 0.8 ((100 cm)/(1 cm))^2

= 0.8·100^2 = 8000

Fiona can cut 8000 rectangles from the plastic sheeting she bought.

5 0

3 years ago

Which equation represents the model shown below

Alona [7]

Answer:

-4x - 3 = -8

Step-by-step explanation:

On our left, we have -x in 4 places = 4(-x) = -4x

And on the left, we also have -1 in 3 places = 3(-1) = -3

Altogether in our left, we have: -4x +(-3)

That is: -4x - 3

On our right, we have -1 in 8 places, which is 8(-1) = -8

Therefore, the equation that represents the model would be:

-4x - 3 = -8

6 0

3 years ago

Exercise 5.2. Suppose that X has moment generating function

soldi70 [24.7K]

Answer:

a) Mean, E(X) = - 0.5

Variance = = 9.25

b) $M_{X}(t)=E(e^{tX})$

or

⇒ $=\sum e^{tx}p(x)$

⇒ $=\frac{1}{2}+\frac{1}{3}e^{-4t}+\frac{1}{6}e^{5t}$

Step-by-step explanation:

Given:

moment generating function of X as:

MX(t) = $\frac{1}{2} + \frac{1}{3}e^{-4t} + \frac{1}{6} e^{5t}$

a) Now

Mean, E(X) = $M_{X}'(t=0)$

Thus,

$M_{X}'(t)=\frac{1}{3}(-4)e^{-4t}+\frac{1}{6}(5)e^{5t}$

or

$M_{X}'(t)=\frac{-4}{3}e^{-4t}+\frac{5}{6}e^{5t}$

also,

$E(X^{2})=M_{X}''(t=0)$

Thus,

$M_{X}''(t)=\frac{-4}{3}(-4)e^{-4t}+\frac{5}{6}(5)e^{5t}$

or

$M_{X}''(t)=\frac{16}{3}e^{-4t}+\frac{25}{6}e^{5t}$

Therefore,

Mean, E(X) = $M_{X}'(t=0)=\frac{-4}{3}e^{-4(0)}+\frac{5}{6}e^{5(0)}$

or

Mean, E(X) = - 0.5

and

$E(X^{2})=M_{X}''(t=0)=\frac{16}{3}e^{-4(0)}+\frac{25}{6}e^{5(0)}$

or

$E(X^{2})$ = 9.5

also,

Variance(X) = E(X²) - E(X)²

⇒ 9.5 - (-0.5)²

= 9.25

b) Now,

Let f(x) be the PMF of X

Thus,

$M_{X}(t)=E(e^{tX})$

or

⇒ $=\sum e^{tx}p(x)$

⇒ $=\frac{1}{2}+\frac{1}{3}e^{-4t}+\frac{1}{6}e^{5t}$

Therefore,

at x = 0, P(x) = $\frac{1}{2}$

at x= - 4 ,P(x) = $\frac{1}{3}$

at x = 5, P(x) = $\frac{1}{6}$

Thus,

E(X) = $\sum xP(x)=0(\frac{1}{2})+(-4)(\frac{1}{3})+5(\frac{1}{6})$

or

E(X) = - 0.5

also, $E(X^{2})=\sum x^{2}P(x)=0^{2}(\frac{1}{2})+(-4)^{2}(\frac{1}{3})+5^{2}(\frac{1}{6})$

$E(X^{2})$ = 9.5

Hence,

Var(X) = E(X²) - E(X)²

⇒ 9.5 - (-0.5)²

= 9.25

4 0

4 years ago