Chapter 2
Algebra and Trigonometry with Analytic Geometry · 428 exercises
Problem 15
Exer. 1-34: Write the expression in the form \(a+b i\), where \(a\) and \(b\) are real numbers. (a) \(i^{43}\) (b) \(i^{-20}\)
5 step solution
Problem 16
Solve the equation. $$\frac{3}{y}+\frac{6}{y}-\frac{1}{y}=11$$
4 step solution
Problem 16
Exer. 1-40: Solve the inequality, and express the solutions in terms of intervals whenever possible. $$ 25 x^{2}-9 x<0 $$
6 step solution
Problem 16
Exer. 13-20: Express the interval as an inequality in the variable \(x\). $$ (3,7) $$
2 step solution
Problem 16
Exer. 1-50: Solve the equation. $$ \sqrt[3]{6-s^{2}}+5=0 $$
4 step solution
Problem 16
Exer. 1-34: Write the expression in the form \(a+b i\), where \(a\) and \(b\) are real numbers. (a) \(i^{92}\) (b) \(i^{-33}\)
3 step solution
Problem 16
Exer. 15-16: Determine whether the two equations are equivalent. (a) \(x^{2}=25, x=5\) (b) \(x=\sqrt{64}, x=8\)
3 step solution
Problem 17
Two children, who are 224 meters apart, start walking toward each other at the same instant at rates of \(1.5 \mathrm{~m} / \mathrm{sec}\) and \(2 \mathrm{~m} / \mathrm{sec}\), respectively (see the figure). (a) When will they meet? (b) How far will each have walked?
5 step solution
Problem 17
Solve the equation. $$(3 x-2)^{2}=(x-5)(9 x+4)$$
4 step solution
Problem 17
Exer. 1-40: Solve the inequality, and express the solutions in terms of intervals whenever possible. $$ 16 x^{2} \geq 9 x $$
5 step solution
Problem 17
Exer. 13-20: Express the interval as an inequality in the variable \(x\). $$ [4, \infty) $$
3 step solution
Problem 17
Exer. 1-50: Solve the equation. $$ \sqrt[5]{2 x^{2}+1}-2=0 $$
5 step solution
Problem 17
Exer. 1-34: Write the expression in the form \(a+b i\), where \(a\) and \(b\) are real numbers. (a) \(i^{73}\) (b) \(i^{-46}\)
3 step solution
Problem 18
A runner starts at the beginning of a runners' path and runs at a constant rate of \(6 \mathrm{mi} / \mathrm{hr}\). Five minutes later a second runner begins at the same point, running at a rate of \(8 \mathrm{mi} / \mathrm{hr}\) and following the same course. How long will it take the second runner to reach the first?
6 step solution
Problem 18
Solve the equation. $$(x+5)^{2}+3=(x-2)^{2}$$
5 step solution
Problem 18
Exer. 1-40: Solve the inequality, and express the solutions in terms of intervals whenever possible. $$ 16 x^{2}>9 $$
8 step solution
Problem 18
Exer. 13-20: Express the interval as an inequality in the variable \(x\). $$ (-3, \infty) $$
2 step solution
Problem 18
Exer. 1-50: Solve the equation. $$ \sqrt[4]{2 x^{2}-1}=x $$
6 step solution
Problem 18
Exer. 1-34: Write the expression in the form \(a+b i\), where \(a\) and \(b\) are real numbers. (a) \(i^{66}\) (b) \(i^{-55}\)
3 step solution
Problem 19
At 6 A.M. a snowplow, traveling at a constant speed, begins to clear a highway leading out of town. At \(8 \mathrm{~A} . \mathrm{M}\). an automobile begins traveling the highway at a speed of \(30 \mathrm{mi} / \mathrm{hr}\) and reaches the plow \(30 \mathrm{minutes}\) later. Find the speed of the snowplow.
6 step solution
Problem 19
Solve the equation. $$(5 x-7)(2 x+1)-10 x(x-4)=0$$
6 step solution
Problem 19
Exer. 1-40: Solve the inequality, and express the solutions in terms of intervals whenever possible. $$ x^{4}+5 x^{2} \geq 36 $$
7 step solution
Problem 19
Exer. 13-20: Express the interval as an inequality in the variable \(x\). $$ (-\infty,-5) $$
2 step solution
Problem 19
Exer. 1-50: Solve the equation. $$ \sqrt{7-x}=x-5 $$
7 step solution
Problem 19
Exer. 1-34: Write the expression in the form \(a+b i\), where \(a\) and \(b\) are real numbers. $$ \frac{3}{2+4 i} $$
6 step solution
Problem 20
Two children own two-way radios that have a maximum range of 2 miles. One leaves a certain point at 1:00 P.M., walking due north at a rate of \(4 \mathrm{mi} / \mathrm{hr}\). The other leaves the same point at 1:15 P.M., traveling due south at \(6 \mathrm{mi} / \mathrm{hr}\). When will they be unable to communicate with one another?
5 step solution
Problem 20
Solve the equation. $$(2 x+9)(4 x-3)=8 x^{2}-12$$
4 step solution
Problem 20
Exer. 1-40: Solve the inequality, and express the solutions in terms of intervals whenever possible. $$ x^{4}+15 x^{2}<16 $$
6 step solution
Problem 20
Exer. 13-20: Express the interval as an inequality in the variable \(x\). $$ (-\infty, 2] $$
2 step solution
Problem 20
Exer. 1-50: Solve the equation. $$ \sqrt{3-x}-x=3 $$
6 step solution
Problem 20
Exer. 1-34: Write the expression in the form \(a+b i\), where \(a\) and \(b\) are real numbers. $$ \frac{5}{2-7 i} $$
6 step solution
Problem 21
Solve the equation. $$\frac{3 x+1}{6 x-2}=\frac{2 x+5}{4 x-13}$$
5 step solution
Problem 21
Exer. 1-40: Solve the inequality, and express the solutions in terms of intervals whenever possible. $$ x^{3}+2 x^{2}-4 x-8 \geq 0 $$
7 step solution
Problem 21
Exer. 21-70: Solve the inequality, and express the solutions in terms of intervals whenever possible. $$ 3 x-2>14 $$
3 step solution
Problem 21
Exer. 1-50: Solve the equation. $$ 3 \sqrt{2 x-3}+2 \sqrt{7-x}=11 $$
5 step solution
Problem 21
Exer. 1-34: Write the expression in the form \(a+b i\), where \(a\) and \(b\) are real numbers. $$ \frac{1-7 i}{6-2 i} $$
6 step solution
Problem 22
A salesperson purchased an automobile that was advertised as averaging \(25 \mathrm{mi} / \mathrm{gal}\) in the city and \(40 \mathrm{mi} / \mathrm{gal}\) on the highway. A recent sales trip that covered 1800 miles required 51 gallons of gasoline. Assuming that the advertised mileage estimates were correct, how many miles were driven in the city?
6 step solution
Problem 22
Solve the equation. $$\frac{5 x+2}{10 x-3}=\frac{x-8}{2 x+3}$$
5 step solution
Problem 22
Exer. 1-40: Solve the inequality, and express the solutions in terms of intervals whenever possible. $$ 2 x^{3}-3 x^{2}-2 x+3 \leq 0 $$
6 step solution
Problem 22
Exer. 21-70: Solve the inequality, and express the solutions in terms of intervals whenever possible. $$ 2 x+5 \leq 7 $$
3 step solution
Problem 22
Exer. 1-50: Solve the equation. $$ \sqrt{2 x+15}-2=\sqrt{6 x+1} $$
9 step solution
Problem 22
Exer. 1-34: Write the expression in the form \(a+b i\), where \(a\) and \(b\) are real numbers. $$ \frac{2+9 i}{-3-i} $$
5 step solution
Problem 23
A bullet is fired horizontally at a target, and the sound of its impact is heard \(1.5\) seconds later. If the speed of the bullet is \(3300 \mathrm{ft} / \mathrm{sec}\) and the speed of sound is \(1100 \mathrm{ft} / \mathrm{sec}\), how far away is the target?
6 step solution
Problem 23
Solve the equation. $$\frac{2}{5}+\frac{4}{10 x+5}=\frac{7}{2 x+1}$$
5 step solution
Problem 23
Exer. 1-40: Solve the inequality, and express the solutions in terms of intervals whenever possible. $$ \frac{x^{2}(x+2)}{(x+2)(x+1)} \leq 0 $$
4 step solution
Problem 23
Exer. 21-70: Solve the inequality, and express the solutions in terms of intervals whenever possible. $$ -2-3 x \geq 2 $$
3 step solution
Problem 23
Exer. 1-50: Solve the equation. $$ x=4+\sqrt{4 x-19} $$
5 step solution
Problem 23
Exer. 1-34: Write the expression in the form \(a+b i\), where \(a\) and \(b\) are real numbers. $$ \frac{-4+6 i}{2+7 i} $$
7 step solution
Problem 24
A woman begins jogging at \(3: 00\) P.M., running due north at a 6-minute-mile pace. Later, she reverses direction and runs due south at a 7-minute-mile pace. If she returns to her starting point at \(3: 45\) P.M., find the total number of miles run.
7 step solution
Problem 24
Solve the equation. $$\frac{-5}{3 x-9}+\frac{4}{x-3}=\frac{5}{6}$$
6 step solution