Chapter 2

Elementary Algebra Within Reach · 316 exercises

Problem 30

In Exercises \(25-32\), simplify the expression by combining like terms. $$ 10 x-6-5 x $$

3 step solution

Problem 30

In Exercises 19-36, expand the expression as a product of factors. $$ 2(x z)^{4} $$

2 step solution

Problem 31

In Exercises 27-32, solve the equation. $$ 3 x=30 $$

3 step solution

Problem 31

In Exercises \(25-32\), simplify the expression by combining like terms. $$ 5 r+6-2 r+1 $$

3 step solution

Problem 31

In Exercises 19-36, expand the expression as a product of factors. $$ (x+y)^{2} $$

2 step solution

Problem 32

In Exercises 27-32, solve the equation. $$ \frac{3}{2} x=9 $$

4 step solution

Problem 32

In Exercises \(25-32\), simplify the expression by combining like terms. $$ 2 t-4+8 t+9 $$

2 step solution

Problem 32

In Exercises 19-36, expand the expression as a product of factors. $$ (s-t)^{5} $$

4 step solution

Problem 33

In Exercises 33-38, justify each step of the equation. Then identify any properties of equality used to solve the equation. $$ \begin{aligned} x-8 &=3 \\ x-8+8 &=3+8 \\ x &=11 \end{aligned} $$

3 step solution

Problem 33

$$ \text { In Exercises 33-46, simplify the expression. } $$ $$ 2(6 x) $$

3 step solution

Problem 33

In Exercises 19-36, expand the expression as a product of factors. $$ \left(\frac{a}{3 s}\right)^{4} $$

4 step solution

Problem 34

In Exercises 33-38, justify each step of the equation. Then identify any properties of equality used to solve the equation. $$ \begin{aligned} x+4 &=16 \\ x+4-4 &=16-4 \\ x &=12 \end{aligned} $$

3 step solution

Problem 34

$$ \text { In Exercises 33-46, simplify the expression. } $$ $$ -7(5 a) $$

2 step solution

Problem 34

In Exercises 19-36, expand the expression as a product of factors. $$ \left(-\frac{2}{5 x}\right)^{3} $$

3 step solution

Problem 35

In Exercises 33-38, justify each step of the equation. Then identify any properties of equality used to solve the equation. $$ \begin{aligned} \frac{2}{3} x &=12 \\ \frac{3}{2}\left(\frac{2}{3} x\right) &=\frac{3}{2}(12) \\ x &=18 \end{aligned} $$

4 step solution

Problem 35

$$ \text { In Exercises 33-46, simplify the expression. } $$ $$ -(4 x) $$

3 step solution

Problem 35

In Exercises 19-36, expand the expression as a product of factors. $$ \left[2(a-b)^{3}\right]\left[2(a-b)^{2}\right] $$

4 step solution

Problem 36

In Exercises 33-38, justify each step of the equation. Then identify any properties of equality used to solve the equation. $$ \begin{aligned} \frac{4}{5} x &=-28 \\ \frac{5}{4}\left(\frac{4}{5} x\right) &=\frac{5}{4}(-28) \\ x &=-35 \end{aligned} $$

3 step solution

Problem 36

In Exercises 23-36, write a verbal description of the algebraic expression, without using a variable. (There is more than one correct answer.) $$ x^{3}-1 $$

3 step solution

Problem 36

$$ \text { In Exercises 33-46, simplify the expression. } $$ $$ -(5 t) $$

4 step solution

Problem 36

In Exercises 19-36, expand the expression as a product of factors. $$ \left[3(r+s)^{2}\right][3(r+s)]^{2} $$

4 step solution

Problem 37

In Exercises 33-38, justify each step of the equation. Then identify any properties of equality used to solve the equation. $$ \begin{aligned} 5 x+12 &=22 \\ 5 x+12-12 &=22-12 \\ 5 x &=10 \\ \frac{5 x}{5} &=\frac{10}{5} \\ x &=2 \end{aligned} $$

5 step solution

Problem 37

The sales tax on a purchase of \(L\) dollars is \(6 \%\). Write an algebraic expression that represents the total amount of sales tax. (Hint: Use the decimal form of \(6 \%\).)

2 step solution

Problem 37

$$ \text { In Exercises 33-46, simplify the expression. } $$ $$ (-2 x)(-3 x) $$

4 step solution

Problem 37

In Exercises 37-44, evaluate the algebraic expression for the given values of the variable(s). \(2 x-1\) (a) \(x=\frac{1}{2}\) (b) \(x=-4\)

4 step solution

Problem 38

In Exercises 33-38, justify each step of the equation. Then identify any properties of equality used to solve the equation. $$ \begin{aligned} 14-3 x &=5 \\ 14-3 x-14 &=5-14 \\ 14-14-3 x &=5-14 \\ -3 x &=-9 \\ \frac{-3 x}{-3} &=\frac{-9}{-3} \\ x &=3 \end{aligned} $$

5 step solution

Problem 38

The state income tax on a gross income of \(I\) dollars in Pennsylvania is \(3.07 \%\). Write an algebraic expression that represents the total amount of income tax.

3 step solution

Problem 38

$$ \text { In Exercises 33-46, simplify the expression. } $$ $$ (-3 y)(-4 y) $$

4 step solution

Problem 38

In Exercises 37-44, evaluate the algebraic expression for the given values of the variable(s). \(3 x-2\) (a) \(x=\frac{4}{3}\) (b) \(x=-1\)

3 step solution

Problem 39

In Exercises 39-42, write an algebraic equation. Do not solve the equation. After your instructor added 6 points to each student's test score, your score is 94 . What was your original score?

2 step solution

Problem 39

A movie rental costs \(\$ 3\) per day. A video game rental costs \(\$ 4\) per day. Write an algebraic expression that represents the total cost of renting \(m\) movies and \(v\) video games per day.

3 step solution

Problem 39

$$ \text { In Exercises 33-46, simplify the expression. } $$ $$ (-5 z)\left(2 z^{2}\right) $$

3 step solution

Problem 39

In Exercises 37-44, evaluate the algebraic expression for the given values of the variable(s). \(2 x^{2}-5\) (a) \(x=2\) (b) \(x=3\)

4 step solution

Problem 40

In Exercises 39-42, write an algebraic equation. Do not solve the equation. With the \(1.2\)-inch rainfall today, the total for the month is \(4.5\) inches. How much had been recorded for the month before today's rainfall?

2 step solution

Problem 40

The height of a rectangular picture frame is \(1.5\) times the width \(w\). Write an algebraic expression that represents the perimeter of the picture frame.

3 step solution

Problem 40

$$ \text { In Exercises 33-46, simplify the expression. } $$ $$ (10 t)\left(-4 t^{2}\right) $$

3 step solution

Problem 40

In Exercises 37-44, evaluate the algebraic expression for the given values of the variable(s). \(64-16 t^{2}\) (a) \(t=2\) (b) \(t=3\)

2 step solution

Problem 41

In Exercises 39-42, write an algebraic equation. Do not solve the equation. During a football game, a running back carried the ball 18 times and his average number of yards per carry was \(4.5\). How many yards did the running back gain for the game?

3 step solution

Problem 41

An employee's hourly wage is \(\$ 12.50\) per hour plus \(\$ 0.75\) for each of the \(q\) units produced during the hour. Write an algebraic expression that represents the employee's total hourly earnings.

3 step solution

Problem 41

$$ \text { In Exercises 33-46, simplify the expression. } $$ $$ \frac{18 a}{5} \cdot \frac{15}{6} $$

4 step solution

Problem 41

In Exercises 37-44, evaluate the algebraic expression for the given values of the variable(s). \(3 x-2 y\) (a) \(x=4, y=3\)

4 step solution

Problem 42

In Exercises 39-42, write an algebraic equation. Do not solve the equation. The total cost of admission for 6 adults at an aquarium is \(\$ 132\). What is the cost per adult?

2 step solution

Problem 42

A campground charges \(\$ 15\) for adults and \(\$ 2\) for children. Write an algebraic expression that represents the total camping fee for \(m\) adults and \(n\) children,

3 step solution

Problem 42

$$ \text { In Exercises 33-46, simplify the expression. } $$ $$ \frac{5 x}{8} \cdot \frac{16}{5} $$

4 step solution

Problem 42

In Exercises 37-44, evaluate the algebraic expression for the given values of the variable(s). \(10 u-3 v\) (a) \(u=3, v=10\) (b) \(u=-2, v=\frac{4}{7}\)

4 step solution

Problem 43

You want to volunteer at a soup kitchen for 150 hours over a 15 -week period. After 8 weeks, you have volunteered for 72 hours. How many hours will you have to work per week over the remaining 7 weeks to reach your goal?

2 step solution

Problem 43

Applications for a cellular phone cost \(\$ 0.99\) each. Ringtones cost \(\$ 1.99\) each. Write an algebraic expression that represents the total cost of buying \(a\) applications and \(r\) ringtones.

3 step solution

Problem 43

$$ \text { In Exercises 33-46, simplify the expression. } $$ $$ \left(-\frac{3 x^{2}}{2}\right)\left(\frac{4 x}{18}\right) $$

5 step solution

Problem 43

In Exercises 37-44, evaluate the algebraic expression for the given values of the variable(s). \(x-3(x-y)\) (a) \(x=3, y=3\) (b) \(x=4, y=-4\)

4 step solution

Problem 44

A textile corporation buys equipment with an initial purchase price of \(\$ 750,000\). It is estimated that its useful life will be 3 years and at that time its value will be \(\$ 75,000\). The total depreciation is divided equally among the three years. (Depreciation is the difference between the initial price of an item and its current value.) What is the total amount of depreciation declared each year?

3 step solution

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