Chapter 1

College Algebra · 657 exercises

Problem 74

Absolute value expressions are equal when the expressions inside the absolute value bars are equal to or opposites of each other. $$ |2 x-7|=|x+3| $$

3 step solution

Problem 74

In Exercises \(57-76,\) solve each formula for the specified variable. Do you recognize the formula? If so, what does it describe? \(A=2 l w+2 l h+2 w h\) for \(h\)

4 step solution

Problem 74

Solve each inequality in Exercises 57-84 by first rewriting each one as an equivalent inequality without absolute value bars. Graph the solution set on a number line. Express the solution set using interval notation. $$\left|\frac{3 x-3}{9}\right| \geq 1$$

4 step solution

Problem 74

The equation \(P=-0.5 d+100\) describes the percentage, \(P,\) of lost hikers found in search and rescue missions when members of the search team walk parallel to one another separated by a distance of \(d\) yards. If a search and rescue team finds \(70 \%\) of lost hikers, find the parallel distance of separation between members of the search party.

4 step solution

Problem 75

Solve each equation in Exercises \(73-98\) by the method of your choice. \(5 x^{2}+2=11 x\)

3 step solution

Problem 75

Solve each equation by the method of your choice. $$ x+2 \sqrt{x}-3=0 $$

4 step solution

Problem 75

In Exercises \(57-76,\) solve each formula for the specified variable. Do you recognize the formula? If so, what does it describe? \(\frac{1}{p}+\frac{1}{q}=\frac{1}{f}\) for \(f\)

4 step solution

Problem 75

Solve each inequality in Exercises 57-84 by first rewriting each one as an equivalent inequality without absolute value bars. Graph the solution set on a number line. Express the solution set using interval notation. $$\left|3-\frac{2}{3} x\right|>5$$

4 step solution

Problem 75

What is a linear equation in one variable? Give an example of this type of equation.

3 step solution

Problem 76

Solve each equation in Exercises \(73-98\) by the method of your choice. \(5 x^{2}=6-13 x\)

5 step solution

Problem 76

Solve each equation by the method of your choice. $$ x^{3}+3 x^{2}-4 x-12=0 $$

3 step solution

Problem 76

Solve each inequality in Exercises 57-84 by first rewriting each one as an equivalent inequality without absolute value bars. Graph the solution set on a number line. Express the solution set using interval notation. $$\left|3-\frac{3}{4} x\right|>9$$

3 step solution

Problem 76

What does it mean to solve an equation?

4 step solution

Problem 77

Solve each equation in Exercises \(73-98\) by the method of your choice. \(3 x^{2}=60\)

3 step solution

Problem 77

Solve each equation by the method of your choice. $$ (x+4)^{3 / 2}=8 $$

3 step solution

Problem 77

What is a formula?

3 step solution

Problem 77

Solve each inequality by first rewriting each one as an equivalent inequality without absolute value bars. Graph the solution set on a number line. Express the solution set using interval notation. $$3|x-1|+2 \geq 8$$

4 step solution

Problem 77

What is the solution set of an equation?

2 step solution

Problem 78

Solve each equation in Exercises \(73-98\) by the method of your choice. \(2 x^{2}=250\)

3 step solution

Problem 78

Solve each equation by the method of your choice. $$ \left(x^{2}-1\right)^{2}-2\left(x^{2}-1\right)=3 $$

4 step solution

Problem 78

We discussed formulas in this section after we considered procedures for solving linear equations. Doesn't working -with a formula simply mean substituting given numbers Jinto the formula and using the order of operations? Is it necessary to know how to solve equations to work with formulas? Explain.

3 step solution

Problem 78

Solve each inequality by first rewriting each one as an equivalent inequality without absolute value bars. Graph the solution set on a number line. Express the solution set using interval notation. $$-2|4-x| \geq-4$$

5 step solution

Problem 78

What are equivalent equations? Give an example.

2 step solution

Problem 79

Solve each equation in Exercises \(73-98\) by the method of your choice. \(x^{2}-2 x=1\)

3 step solution

Problem 79

Solve each equation by the method of your choice. $$ \sqrt{4 x+15}-2 x=0 $$

5 step solution

Problem 79

In your own words, describe a step-by-step approach for solving algebraic word problems.

5 step solution

Problem 79

Solve each inequality by first rewriting each one as an equivalent inequality without absolute value bars. Graph the solution set on a number line. Express the solution set using interval notation. $$3<|2 x-1|$$

4 step solution

Problem 79

What is the difference between solving an equation such as \(2(x-4)+5 x=34\) and simplifying an algebraic expression such as \(2(x-4)+5 x ?\) If there is a difference, which topic should be taught first? Why?

4 step solution

Problem 80

Solve each equation in Exercises \(73-98\) by the method of your choice. \(2 x^{2}+3 x=1\)

3 step solution

Problem 80

Solve each equation by the method of your choice. $$ x^{2 / 5}-1=0 $$

3 step solution

Problem 80

Did you have some difficulties solving some of the problems that were assigned in this exercise set? Discuss what you did if this happened to you. Did your course of action enhance your ability to solve algebraic word problems?

3 step solution

Problem 80

Solve each inequality by first rewriting each one as an equivalent inequality without absolute value bars. Graph the solution set on a number line. Express the solution set using interval notation. $$5 \geq|4-x|$$

4 step solution

Problem 80

Suppose that you solve \(\frac{x}{5}-\frac{x}{2}=1\) by multiplying both sides by \(20,\) rather than the least common denominator of 5 and 2 (namely, 10 ). Describe what happens. If you get the correct solution, why do you think we clear the equation of fractions by multiplying by the least common denominator?

3 step solution

Problem 81

Solve each equation in Exercises 73-98 by the method of your choice. \((2 x+3)(x+4)=1\)

4 step solution

Problem 81

Solve each equation by the method of your choice. $$ \left|x^{2}+2 x-36\right|=12 $$

5 step solution

Problem 81

Solve each inequality by first rewriting each one as an equivalent inequality without absolute value bars. Graph the solution set on a number line. Express the solution set using interval notation. $$12<\left|-2 x+\frac{6}{7}\right|+\frac{3}{7}$$

3 step solution

Problem 81

A. Suppose you are an algebra teacher grading the following solution on an examination: $$\begin{aligned} -3(x-6) &=2-x \\ -3 x-18 &=2-x \\ -2 x-18 &=2 \\ -2 x &=-16 \\ x &=8 \end{aligned}$$ You should note that 8 checks, and the solution set is \(\\{8\\} .\) The student who worked the problem therefore wants full credit. Can you find any errors in the solution? If full credit is 10 points, how many points should you give the student? Justify your position.

5 step solution

Problem 82

Solve each equation in Exercises 73-98 by the method of your choice. \((2 x-5)(x+1)=2\)

3 step solution

Problem 82

Solve each equation by the method of your choice. $$ \sqrt{3 x+1}-\sqrt{x-1}=2 $$

4 step solution

Problem 82

A tennis club offers two payment options. Members can pay a monthly fee of \(\$ 30\) plus \(\$ 5\) per hour for court rental time. The second option has no monthly fee, but court time costs \(\$ 7.50\) per hour. a. Write a mathematical model representing total monthly costs for each option for \(x\) hours of court rental time. b. Use a graphing utility to graph the two models in \(\mathbf{a}[0,15,1]\) by \([0,120,20]\) viewing rectangle. c. Use your utility's trace or intersection feature to determine where the two graphs intersect. Describe what the coordinates of this intersection point represent in practical terms. d. Verify part (c) using an algebraic approach by setting the two models equal to one another and determining how many hours one has to rent the court so that the two plans result in identical monthly costs.

4 step solution

Problem 82

Solve each inequality by first rewriting each one as an equivalent inequality without absolute value bars. Graph the solution set on a number line. Express the solution set using interval notation. $$1<\left|x-\frac{11}{3}\right|+\frac{7}{3}$$

4 step solution

Problem 82

Explain how to determine the restrictions on the variable for the equation $$ \frac{3}{x+5}+\frac{4}{x-2}=\frac{7}{(x+5)(x-2)} $$

3 step solution

Problem 83

Solve each equation in Exercises 73-98 by the method of your choice. \((3 x-4)^{2}=16\)

3 step solution

Problem 83

Solve each equation by the method of your choice. $$ x^{3}-2 x^{2}=x-2 $$

6 step solution

Problem 83

Solve each inequality by first rewriting each one as an equivalent inequality without absolute value bars. Graph the solution set on a number line. Express the solution set using interval notation. $$4+\left|3-\frac{x}{3}\right| \geq 9$$

4 step solution

Problem 83

What is an identity? Give an example.

2 step solution

Problem 84

Solve each equation in Exercises 73-98 by the method of your choice. \((2 x+7)^{2}=25\)

4 step solution

Problem 84

Solve each equation by the method of your choice. $$ \left|x^{2}+6 x+1\right|=8 $$

4 step solution

Problem 84

Solve each inequality by first rewriting each one as an equivalent inequality without absolute value bars. Graph the solution set on a number line. Express the solution set using interval notation. $$\left|2-\frac{x}{2}\right|-1 \leq 1$$

5 step solution

Problem 84

What is a conditional equation? Give an example.

3 step solution

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