Graph each system of constraints. Name all vertices. Then find the values of x and y that maximize or minimize the objective function. x + y ≤ 5, x + 2y ≤ 8, x ≥ 0, y ≥ 0

Di qué hicieron las siguientes personas durante su excursión al aire libre.
Elena / divertirse al aire libre

Silicon forms a series of compounds that is analogous to alkanes and has the general formula $\mathrm{Si}_{\mathrm{n}} \mathrm{H}_{2 \mathrm{n}+2}$. The first of these compounds is silane, $\mathrm{SiH}_4$, which is used in the electronics industry to produce thin ultrapure silicon films. $\mathrm{SiH}_4(\mathrm{~g})$ is somewhat difficult to work with because it is pyrophoric at room temperature-meaning that it bursts into flame spontaneously.

(a) Write an equation for the combustion of $\mathrm{SiH}_4(\mathrm{~g})$. (The reaction is analogous to hydrocarbon combustion, and $\mathrm{SiO}_2$ is a solid under standard conditions. Assume the water produced will be a gas.)

(b) Use the data from Appendix $\mathrm{E}$ to calculate $\Delta S^{\circ}$ for this reaction.

(c) Calculate $\Delta G^{\circ}$ and show that the reaction is spontaneous at $25^{\circ} \mathrm{C}$.

(d) Compare $\Delta G^{\circ}$ for this reaction to the combustion of methane. Are the reactions in these two exercises enthalpy or entropy driven? Explain.

The current and estimated resident populations (in percent) of blacks and Hispanics in the United States for the years $1990-2050$ are modeled by the linear functions defined below.

$$\begin{array}{ll} y=.0515 x+12.3 & \text { Blacks } \\ y=.255 x+9.01 & \text { Hispanics } \end{array}$$

In the case, $x$ represents the number of years since 1990.

($c$) Use a calculator graph of the system to support your algebraic solution.

A researcher wants to know if the octane level of gasoline affects the gas mileage of a car. She randomly selects 10 cars and puts 5 gallons of 87-octane gasoline in the tank. On a closed track, each car is driven at 50 miles per hour until it runs out of gas. The experiment is repeated, with each car getting 5 gallons of 92-octane gasoline. The miles per gallon for each car are then computed. The results are shown. Would you recommend purchasing 92 octane? Why or why not?

$$\begin{matrix} \text{87 Octane} & \text{92 Octane} & \text{87 Octane} & \text{92 Octane}\\ \text{18.0} & \text{18.5} & \text{23.4} & \text{22.8}\\ \text{23.2} & \text{23.1} & \text{23.1} & \text{23.5}\\ \text{31.5} & \text{31.9} & \text{19.0} & \text{19.5}\\ \text{24.9} & \text{26.7} & \text{26.8} & \text{26.2}\\ \text{24.1} & \text{25.1} & \text{31.8} & \text{30.7}\\ \end{matrix}$$

Decode the following ciphertext messages that were encoded using a Caesar cipher with the given key. a. JUUBFNUUCQJCNWMBFNUU, k = 9 b. XAEWFVMPPMKERHXLIWPMXLCXSZIWHMHKCVIERHKMQFPIMRXLIAEFI, k = 4 c. IURSAYZGXJCOZNZNKQTOLKOTZNKROHXGXE, k = 6

When interest is compounded continuously, the amount of money increases at a rate proportional to the amount S present at time t, that is, d S / d t=r S, where r is the annual rate of interest.

Find the amount of money accrued at the end of 5 years when $5000 is deposited in a savings account drawing$5 $\frac{3}{4}$ %$ annual interest compounded continuously.

Determine the scale factor for triangle $ABC$ to triangle $A'B'C'$.

A) $10$; B) $20$; C) $2$; D) $\dfrac{1}{2}$.

Complete and balance the following chemical equations: (a) hardening of plaster containing slaked lime

$$\mathrm{Ca}(\mathrm{OH})_2+\mathrm{CO}_2 \longrightarrow$$

(b) removal of sulfur dioxide from the flue gas of power plants

$$\mathrm{CaO}+\mathrm{SO}_2 \longrightarrow$$

(c) the reaction of baking powder that produces carbon dioxide gas and causes bread to rise

$$\mathrm{NaHCO}_3+\mathrm{NaH}_2 \mathrm{PO}_4 \longrightarrow$$

In paragraph $67$, Hemingway writes, “Krebs looked at the bacon fat hardening on his plate.” What does that image suggest about Krebs? How does it contribute to the story? In paragraph $85$, Hemingway writes, “Krebs felt sick and vaguely nauseated.” How would you explain the causes of his unease?

Suppose the circuit described by the equation below

$$\frac{dI}{dt}+\frac{R}{L}I= \frac{1}{L}V(t)$$

is driven by a sinusoidal voltage source $V(t)=V \sin \omega t$ (where $V$ and $\omega$ are constant).

(a) Show that

$$I(t)=\frac{V}{R^2+L^2 \omega^2}(R \sin \omega t-L \omega \cos \omega t)+C e^{-(R / L) t}$$

(b) Let $Z=\sqrt{R^2+L^2 \omega^2}$. Choose $\theta$ so that $Z \cos \theta=R$ and $Z \sin \theta=$ $L \omega$. Use the addition formula for the sine function to show that

$$I(t)=\frac{V}{Z} \sin (\omega t-\theta)+C e^{-(R / L) t}$$

This shows that the current in the circuit varies sinusoidally apart from a DC term (called the transient current in electronics) that decreases exponentially.

Refer to the case related to Kevin Lowe. Given the facts in the case, evaluate using deontological and teleological reasoning whether Kevin should take work home and not charge it to the job. What about engaging in ghost-ticking?

Professor Grant Alexander wanted to find a linear model that relates the number of hours a student plays video games each week, h, to the cumulative grade-point average, G, of the student. He obtained a random sample of 10 full-time students at his college and asked each student to disclose the number of hours spent playing video games and the student’s cumulative grade-point average.

$$\begin{matrix} \text{Hours of} & \text{Grade-Point}\\ \text{Video Games} & \text{Average, G}\\ \text{per Week, h} & \text{ }\\ \text{0} & \text{3.49}\\ \text{0} & \text{3.05}\\ \text{2} & \text{3.24}\\ \text{3} & \text{2.82}\\ \text{3} & \text{3.19}\\ \text{5} & \text{2.78}\\ \text{8} & \text{2.31}\\ \text{8} & \text{2.54}\\ \text{10} & \text{2.03}\\ \text{12} & \text{2.51}\\ \end{matrix}$$

How many hours of video game playing do you think a student plays whose grade-point average is 2.40?

When applying LP to diet problems, the objective function is usually designed to:

a) maximize profits from blends of nutrients.

b) maximize ingredient blends.

c) minimize production losses.

d) maximize the number of products to be produced.

e) minimize the costs of nutrient blends.