Chapter 1
Algebra for College Students · 399 exercises
Problem 20
Solve each compound inequality. Graph the solution set, and write it using interval notation. $$ x<5 \text { and } x>0 $$
5 step solution
Problem 20
Translate each verbal sentence into an equation, using \(x\) as the variable. Then solve the equation. $$ \text { When } 75 \% \text { of a number is added to } 6 \text { , the result is } 3 \text { more than the number. Find the number. } $$
3 step solution
Problem 21
Solve each formula for the specified variable. $$\begin{aligned}&A=P(1+r t) \text { for } t\\\&\text { (future value for simple interest) }\end{aligned}$$
4 step solution
Problem 21
Solve each equation, and check the solution. If applicable, tell whether the equation is an identity or a contradiction. \(5 x+2=3 x-6\)
5 step solution
Problem 21
Solve each equation. $$ |0.5 x|=6 $$
4 step solution
Problem 21
Solve each inequality. Graph the solution set, and write it using interval notation. \(-1.3 x \geq-5.2\)
3 step solution
Problem 21
Solve each compound inequality. Graph the solution set, and write it using interval notation. $$ x \leq 2 \text { and } x \leq 5 $$
4 step solution
Problem 21
Determine whether each is an expression or an equation. Simplify any expressions, and solve any equations. $$ 5(x+3)-8(2 x-6) $$
3 step solution
Problem 21
Two steamers leave a port on a river at the same time, traveling in opposite directions. Each is traveling \(22 \mathrm{mph}\). How long will it take for them to be \(110 \mathrm{mi}\) apart?
3 step solution
Problem 22
Solve each formula for the specified variable.$$\begin{aligned}&M=C(1+r) \text { for } r\\\&\text { (markup) }\end{aligned}$$
4 step solution
Problem 22
Solve each equation, and check the solution. If applicable, tell whether the equation is an identity or a contradiction. \(9 x+1=7 x-9\)
4 step solution
Problem 22
Solve each inequality. Graph the solution set, and write it using interval notation. \(-2.5 x \leq-1.25\)
5 step solution
Problem 22
Solve each equation. $$ |0.3 x|=9 $$
5 step solution
Problem 22
Solve each compound inequality. Graph the solution set, and write it using interval notation. $$ x \geq 3 \text { and } x \geq 6 $$
5 step solution
Problem 22
A train leaves Kansas City, Kansas, and travels north at \(85 \mathrm{~km}\) per \(\mathrm{hr}\). Another train leaves at the same time and travels south at \(95 \mathrm{~km}\) per hr. How long will it take before they are \(315 \mathrm{~km}\) apart?
6 step solution
Problem 23
Solve each equation, and check the solution. If applicable, tell whether the equation is an identity or a contradiction. \(7 x-5 x+15=x+8\)
5 step solution
Problem 23
Solve each inequality. Graph the solution set, and write it using interval notation. \(5 x+2 \leq-48\)
6 step solution
Problem 23
Solve each equation. $$ \left|\frac{1}{2} x+3\right|=2 $$
4 step solution
Problem 23
Determine whether each is an expression or an equation. Simplify any expressions, and solve any equations. $$ 5(x+3)-8(2 x-6)=12 $$
5 step solution
Problem 23
Mulder and Scully are driving to Georgia to investigate "Big Blue," a giant reptile reported in one of the local lakes. Mulder leaves the office at 8: 30 A.M. averaging 65 mph. Scully leaves at 9: 00 A.M., following the same path and averaging \(68 \mathrm{mph}\). At what time will Scully catch up with Mulder?
5 step solution
Problem 24
The formula \(F=\frac{9}{5} C+32\) can be solved for \(C\) to obtain \(C=\frac{5}{9}(F-32)\). Which one of the following is not equivalent to this? A. \(C=\frac{5}{9} F-\frac{160}{9}\) B. \(C=\frac{5 F}{9}-\frac{160}{9}\) C. \(C=\frac{5 F-160}{9}\) D. \(C=\frac{5}{9} F-32\)
4 step solution
Problem 24
Solve each equation, and check the solution. If applicable, tell whether the equation is an identity or a contradiction. \(2 x+4-x=4 x-5\)
6 step solution
Problem 24
Solve each inequality. Graph the solution set, and write it using interval notation. \(-2.5 x \leq-1.25\)
4 step solution
Problem 24
Solve each equation. $$ \left|\frac{2}{3} x-1\right|=5 $$
5 step solution
Problem 24
Determine whether each is an expression or an equation. Simplify any expressions, and solve any equations. $$ -7(x+4)+13(x-6)=18 $$
5 step solution
Problem 25
Solve each equation for \(y\). $$4 x+y=1$$
2 step solution
Problem 25
Solve each equation, and check the solution. If applicable, tell whether the equation is an identity or a contradiction. \(12 w+15 w-9+5=-3 w+5-9\)
8 step solution
Problem 25
Solve each equation. $$ \left|1+\frac{3}{4} x\right|=7 $$
4 step solution
Problem 25
Solve each compound inequality. Graph the solution set, and write it using interval notation. $$ x-3 \leq 6 \text { and } x+2 \geq 7 $$
5 step solution
Problem 25
Determine whether each is an expression or an equation. Simplify any expressions, and solve any equations. $$ \frac{1}{2} x-\frac{1}{6} x+\frac{3}{2}-8 $$
4 step solution
Problem 26
Solve each equation for \(y\). $$3 x+y=9$$
2 step solution
Problem 26
Solve each inequality. Graph the solution set, and write it using interval notation. \(\frac{5 x-6}{8}<8\)
5 step solution
Problem 26
Solve each equation, and check the solution. If applicable, tell whether the equation is an identity or a contradiction. \(-4 x+5 x-8+4=6 x-4\)
7 step solution
Problem 26
Solve each equation. $$ \left|2-\frac{5}{2} x\right|=14 $$
4 step solution
Problem 26
Determine whether each is an expression or an equation. Simplify any expressions, and solve any equations. $$ \frac{1}{3} x+\frac{1}{5} x-\frac{1}{2}+7 $$
6 step solution
Problem 26
Sharon commutes to her office by train. When she walks to the train station, it takes her 40 min. When she rides her bike, it takes her 12 min. Her average walking rate is 7 mph less than her average biking rate. Find the distance from her house to the train station. $$ \begin{array}{|l|l|l|l|} \hline & \text { Rate } & \text { Time } & \text { Distance } \\ \text { Walking } & & & \\ \text { Biking } & & & \\ \hline \end{array} $$
6 step solution
Problem 27
Solve each equation for \(y\). $$x-2 y=-6$$
3 step solution
Problem 27
Solve each inequality. Graph the solution set, and write it using interval notation. \(\frac{2 x-5}{-4}>5\)
6 step solution
Problem 27
Solve each equation, and check the solution. If applicable, tell whether the equation is an identity or a contradiction. \(3(2 t-4)=20-2 t\)
6 step solution
Problem 27
Solve each equation. $$ |0.02 x-1|=2.50 $$
5 step solution
Problem 27
Complete the six problem-solving steps to solve each problem. In 2015 , the corporations securing the most U.S. patents were IBM and Samsung. Together, the two corporations secured a total of 12,368 patents, with Samsung receiving 2250 fewer patents than IBM. How many patents did each corporation secure? (Data from U.S. Patent and Trademark Office.) Step 1 Read the problem carefully. We are asked to find ______ . 2 Assign a variable. Let \(x=\) the number of patents that IBM secured. Step Then \(x-2250=\) the number of ______ . Step 3 Write an equation. ____\(+ _____ \ldots=12,368\) Step 4 Solve the equation. \(x=\) ______ . \(\begin{array}{llll}\text { Step } 5 & \text { State the answer. } & \text { IBM secured } & \text { patents. Samsung secured } & \text { patents. }\end{array}\) Step 6 Check. The number of Samsung patents was _____ fewer than the number of _____ The total number of patents was \(7309+\) _____ \(= ______\).
6 step solution
Problem 27
Solve each compound inequality. Graph the solution set, and write it using interval notation. $$ -3 x>3 \text { and } x+3>0 $$
5 step solution
Problem 27
Johnny leaves Memphis to visit his cousin Anne, who lives in the town of Hornsby, Tennessee, 80 mi away. He travels at an average rate of 50 mph. One- half hour later, Anne leaves to visit Johnny, traveling at an average rate of \(60 \mathrm{mph}\). How long after Anne leaves will it be before they meet?
4 step solution
Problem 28
Solve each equation for \(y\). $$x-5 y=-20$$
2 step solution
Problem 28
Solve each inequality. Graph the solution set, and write it using interval notation. \(\frac{3 x-2}{-5}<6\)
4 step solution
Problem 28
Solve each equation, and check the solution. If applicable, tell whether the equation is an identity or a contradiction. \(2(3-2 x)=x-4\)
6 step solution
Problem 28
Solve each equation. $$ |0.04 x-3|=5.96 $$
5 step solution
Problem 28
On an automobile trip, Laura maintained a steady rate for the first two hours. Rush-hour traffic slowed her rate by 25 mph for the last part of the trip. The entire trip, a distance of \(125 \mathrm{mi},\) took \(2 \frac{1}{2} \mathrm{hr} .\) What was her rate during the first part of the trip?
5 step solution
Problem 29
Solve each problem. The John Hancock Center in Chicago has a rectangular base. The length of the base measures \(65 \mathrm{ft}\) less than twice the width. The perimeter of the base is \(860 \mathrm{ft}\). What are the dimensions of the base?
6 step solution
Problem 29
Solve each equation for \(y\). $$4 x+9 y=11$$
2 step solution