Indicate whether the following statements are true or false. Explain. A closed system exergy balance consists of three major contributions: exergy change, exergy transfer, and exergy destruction.

Compute the following products. a. (4x+5)(4x-5), b.

$$( 4 x + 5 ) ^ { 2 }$$

An ac voltmeter with large impedance is connected in turn across the inductor, the capacitor, and the resistor in a series circuit having an alternating emf of 100 V (rms); the meter gives the same reading in volts in each case.What is this reading?

$$\begin{array} { l } { \text { Let } H \text { and } K \text { be subgroups of a group } G \text { and let } H K = \{ h k | h \in H } \\ { k \in K \} \text { and } K H = \{ k h | k \in K , h \in H \} . \text { Prove that } H K \text { is a group if } } \\ { \text { and only if } H K = K H } \end{array}$$

Fill in the blank: If -10 > x then x __ -10.

Sketch the graph of each rational function. $y=\frac{x^{2}-4}{3 x-6}$

Show that each matrix has no inverse.

$$\left[\begin{array}{rrr}{1} & {1} & {-3} \\ {2} & {-4} & {1} \\ {-5} & {7} & {1}\end{array}\right]$$

The data set represents the amounts of time (in minutes) spent checking email for a random sample of employees at a company. 7.5 2.0 12.1 8.8 9.4 7.3 1.9 2.8 7.0 7.3 (a) Find the sample mean and the sample standard deviation. (b) Construct a 90% confidence interval for the population mean. Interpret the results. Assume the times are normally distributed. (c) Repeat part (b), assuming

$$\sigma = 3.5$$

minutes. Interpret and compare the results.

State the absolute value of the number. -34

For

$$y = 2 | 6 - 3 x | + 4 ,$$

which set describes x when y < 6 ?

$$A \{ x | \frac { 5 } { 3 } < x < \frac { 7 } { 3 } \}$$

$$\mathbf { B } \{ x | x < \frac { 5 } { 3 } \text { or } x > \frac { 7 } { 3 } \}$$

$$C \{ x | x < \frac { 5 } { 3 } \}$$

$$\mathbf { D } \{ x | x > \frac { 7 } { 3 } \}$$

Draw a contour map of f(x, y) with an appropriate contour interval, showing at least six level curves.

$$f ( x , y ) = x ^ { 2 } - y$$

For each pairs of terms, explain how the meanings of the terms differ. estuary and freshwater wetland

Use the properties of logarithms to expand each expression.

$$\log _ { 5 } \left( \frac { 2 } { 3 } \right)$$

Use a calculator to find an approximate value for each expression, rounded to two decimal places. $\tan ^{-1}(-2)$