Chapter 4
Introductory Algebra for College Students · 322 exercises
Problem 11
Solve each system by the substitution method. If there is no solution or an infinite number of solutions, so state. Use set notation to express solution sets. $$\left\\{\begin{array}{l}-3 x+y=-1 \\\x-2 y=4\end{array}\right.$$
4 step solution
Problem 11
Graph the solution set of each system of linear inequalities. $$\left\\{\begin{array}{l}y \geq 2 x+1 \\\y \leq 4\end{array}\right.$$
5 step solution
Problem 12
In Exercises \(1-44,\) solve each system by the addition method. If there is no solution or an infinite number of solutions, so state. Use set notation to express solution sets. $$\left\\{\begin{aligned} x+2 y &=-1 \\ 4 x-5 y &=22 \end{aligned}\right.$$
5 step solution
Problem 12
A restaurant purchased eight tablecloths and five napkins for 106 dollar A week later, a tablecloth and six napkins were bought for 24 dollar Find the cost of one tablecloth and the cost of one napkin, assuming the same prices for both purchases.
4 step solution
Problem 12
Solve each system by graphing. If there is no solution or an infinite number of solutions, so state. Use set notation to express solution sets. $$\left\\{\begin{array}{l}x+y=2 \\\x-y=4\end{array}\right.$$
4 step solution
Problem 12
Solve each system by the substitution method. If there is no solution or an infinite number of solutions, so state. Use set notation to express solution sets. $$\left\\{\begin{array}{l}-4 x+y=-11 \\\2 x-3 y=5\end{array}\right.$$
4 step solution
Problem 12
Graph the solution set of each system of linear inequalities. $$\left\\{\begin{array}{l}y \geq \frac{1}{2} x+2 \\\y \leq 2\end{array}\right.$$
3 step solution
Problem 13
In Exercises \(1-44,\) solve each system by the addition method. If there is no solution or an infinite number of solutions, so state. Use set notation to express solution sets. $$\left\\{\begin{array}{rr} -3 x+7 y= & 14 \\ 2 x-y= & -13 \end{array}\right.$$
5 step solution
Problem 13
Solve each system by graphing. If there is no solution or an infinite number of solutions, so state. Use set notation to express solution sets. $$\left\\{\begin{array}{l}x+y=1 \\ y-x=3\end{array}\right.$$
4 step solution
Problem 13
The perimeter of a badminton court is 128 feet. After a game of badminton, a player's coach estimates that the athlete has run a total of 444 feet, which is equivalent to six times the court's length plus nine times its width. What are the dimensions of a standard badminton court?
4 step solution
Problem 13
Solve each system by the substitution method. If there is no solution or an infinite number of solutions, so state. Use set notation to express solution sets. $$\left\\{\begin{array}{l}x=9-2 y \\\x+2 y=13\end{array}\right.$$
3 step solution
Problem 13
Graph the solution set of each system of linear inequalities. $$\left\\{\begin{array}{l}y>x-1 \\\x>5\end{array}\right.$$
3 step solution
Problem 14
In Exercises \(1-44,\) solve each system by the addition method. If there is no solution or an infinite number of solutions, so state. Use set notation to express solution sets. $$\left\\{\begin{array}{l} 2 x-5 y=-1 \\ 3 x+y=7 \end{array}\right.$$
4 step solution
Problem 14
Solve each system by graphing. If there is no solution or an infinite number of solutions, so state. Use set notation to express solution sets. $$\left\\{\begin{array}{l}x+y=4 \\ y-x=4\end{array}\right.$$
4 step solution
Problem 14
The perimeter of a tennis court is 228 feet. After a round of tennis, a player's coach estimates that the athlete has run a total of 690 feet, which is equivalent to 7 times the court's length plus four times its width. What are the dimensions of a standard tennis court?
4 step solution
Problem 14
Solve each system by the substitution method. If there is no solution or an infinite number of solutions, so state. Use set notation to express solution sets. $$\left\\{\begin{array}{l}6 x+2 y=7 \\\y=2-3 x\end{array}\right.$$
4 step solution
Problem 14
Graph the solution set of each system of linear inequalities. $$\left\\{\begin{array}{l}y>x-2 \\\x>3\end{array}\right.$$
4 step solution
Problem 15
In Exercises \(1-44,\) solve each system by the addition method. If there is no solution or an infinite number of solutions, so state. Use set notation to express solution sets. $$\left\\{\begin{array}{l} 3 x-14 y=6 \\ 5 x+7 y=10 \end{array}\right.$$
7 step solution
Problem 15
A rectangular lot whose perimeter is 320 feet is fenced along three sides. An expensive fencing along the lot's length costs 16 dollar per foot. An inexpensive fencing along the two side widths costs only 5 dollar per foot. The total cost of the fencing along the three sides comes to 2140 dollar What are the lot's dimensions?
5 step solution
Problem 15
Solve each system by graphing. If there is no solution or an infinite number of solutions, so state. Use set notation to express solution sets. $$\left\\{\begin{array}{l}2 x-3 y=6 \\ 4 x+3 y=12\end{array}\right.$$
4 step solution
Problem 15
Graph the solution set of each system of linear inequalities. $$\left\\{\begin{array}{l}y \geq 2 x-3 \\\y \leq 2 x+1\end{array}\right.$$
4 step solution
Problem 15
Solve each system by the substitution method. If there is no solution or an infinite number of solutions, so state. Use set notation to express solution sets. $$\left\\{\begin{array}{l}y=3 x-5 \\\21 x-35=7 y\end{array}\right.$$
3 step solution
Problem 16
In Exercises \(1-44,\) solve each system by the addition method. If there is no solution or an infinite number of solutions, so state. Use set notation to express solution sets. $$\left\\{\begin{array}{l} 5 x-4 y=19 \\ 3 x+2 y=7 \end{array}\right.$$
4 step solution
Problem 16
A rectangular lot whose perimeter is 1600 feet is fenced along three sides. An expensive fencing along the lot's length costs 20 dollar per foot. An inexpensive fencing along the two side widths costs only 5 dollar per foot. The total cost of the fencing along the three sides comes to 13,000 dollar What are the lot's dimensions?
3 step solution
Problem 16
Solve each system by graphing. If there is no solution or an infinite number of solutions, so state. Use set notation to express solution sets. $$\left\\{\begin{array}{l}x+2 y=2 \\ x-y=2\end{array}\right.$$
4 step solution
Problem 16
Graph the solution set of each system of linear inequalities. $$\left\\{\begin{array}{l}y \geq 3 x-2 \\\y \leq 3 x+1\end{array}\right.$$
3 step solution
Problem 16
Solve each system by the substitution method. If there is no solution or an infinite number of solutions, so state. Use set notation to express solution sets. $$\left\\{\begin{array}{l}9 x-3 y=12 \\\y=3 x-4\end{array}\right.$$
5 step solution
Problem 17
In Exercises \(1-44,\) solve each system by the addition method. If there is no solution or an infinite number of solutions, so state. Use set notation to express solution sets. $$\left\\{\begin{array}{l} 3 x-4 y=11 \\ 2 x+3 y=-4 \end{array}\right.$$
6 step solution
Problem 17
You are choosing between two telephone plans. Plan A has a monthly fee of 20 dollar with a charge of 0.05 dollar per minute for all calls. Plan B has a monthly fee of 5 dollar with a charge of 0.10 dollar per minute for all calls. a. For how many minutes of calls will the costs for the two plans be the same? What will be the cost for each plan? b. If you make approximately 10 calls per month, each averaging 20 minutes, which plan should you select? Explain your answer.
4 step solution
Problem 17
Solve each system by graphing. If there is no solution or an infinite number of solutions, so state. Use set notation to express solution sets. $$\left\\{\begin{array}{l}4 x+y=4 \\ 3 x-y=3\end{array}\right.$$
4 step solution
Problem 17
Solve each system by the substitution method. If there is no solution or an infinite number of solutions, so state. Use set notation to express solution sets. $$\left\\{\begin{array}{l}5 x+2 y=0 \\\x-3 y=0\end{array}\right.$$
5 step solution
Problem 17
Graph the solution set of each system of linear inequalities. $$\left\\{\begin{array}{l}y>2 x-3 \\\y \leq-x+6\end{array}\right.$$
3 step solution
Problem 18
In Exercises \(1-44,\) solve each system by the addition method. If there is no solution or an infinite number of solutions, so state. Use set notation to express solution sets. $$\left\\{\begin{array}{l} 2 x+3 y=-16 \\ 5 x-10 y=30 \end{array}\right.$$
6 step solution
Problem 18
You are choosing between two telephone plans. Plan A has a monthly fee of 15 dollar with a charge of 0.08 dollar per minute for all calls. Plan B has a monthly fee of 3 dollar with a charge of 0.12 dollar per minute for all calls. a. For how many minutes of calls will the costs for the two plans be the same? What will be the cost for each plan? b. If you make approximately 15 calls per month, each averaging 30 minutes, which plan should you select? Explain your answer.
4 step solution
Problem 18
Solve each system by graphing. If there is no solution or an infinite number of solutions, so state. Use set notation to express solution sets. $$\left\\{\begin{array}{l}5 x-y=10 \\ 2 x+y=4\end{array}\right.$$
3 step solution
Problem 18
Solve each system by the substitution method. If there is no solution or an infinite number of solutions, so state. Use set notation to express solution sets. $$\left\\{\begin{array}{l}4 x+3 y=0 \\\2 x-y=0\end{array}\right.$$
5 step solution
Problem 18
Graph the solution set of each system of linear inequalities. $$\left\\{\begin{array}{l}y<-2 x+4 \\\y \leq x-4\end{array}\right.$$
3 step solution
Problem 19
In Exercises \(1-44,\) solve each system by the addition method. If there is no solution or an infinite number of solutions, so state. Use set notation to express solution sets. $$\left\\{\begin{array}{rr} 3 x+2 y= & -1 \\ -2 x+7 y= & 9 \end{array}\right.$$
6 step solution
Problem 19
You are choosing between two plans at a discount warehouse. Plan A offers an annual membership fee of 100 dollar and you pay \(80 \%\) of the manufacturer's recommended list price. Plan B offers an annual membership fee of 40 dollar and you pay \(90 \%\) of the manufacturer's recommended list price. How many dollars of merchandise would you have to purchase in a year to pay the same amount under both plans? What will be the cost for each plan?
4 step solution
Problem 19
Solve each system by graphing. If there is no solution or an infinite number of solutions, so state. Use set notation to express solution sets. $$\left\\{\begin{array}{l}y=x+5 \\ y=-x+3\end{array}\right.$$
4 step solution
Problem 19
Solve each system by the substitution method. If there is no solution or an infinite number of solutions, so state. Use set notation to express solution sets. $$\left\\{\begin{array}{l}2 x-y=6 \\\3 x+2 y=5\end{array}\right.$$
5 step solution
Problem 19
Graph the solution set of each system of linear inequalities. $$\left\\{\begin{array}{l}x+2 y \leq 4 \\\y \geq x-3\end{array}\right.$$
3 step solution
Problem 20
In Exercises \(1-44,\) solve each system by the addition method. If there is no solution or an infinite number of solutions, so state. Use set notation to express solution sets. $$\left\\{\begin{array}{l} 5 x+3 y=27 \\ 7 x-2 y=13 \end{array}\right.$$
6 step solution
Problem 20
You are choosing between two plans at a discount warehouse. Plan A offers an annual membership fee of 300 dollar and you pay \(70 \%\) of the manufacturer's recommended list price. Plan B offers an annual membership fee of 40 dollar and you pay \(90 \%\) of the manufacturer's recommended list price. How many dollars of merchandise would you have to purchase in a year to pay the same amount under both plans? What will be the cost for each plan?
4 step solution
Problem 20
Solve each system by graphing. If there is no solution or an infinite number of solutions, so state. Use set notation to express solution sets. $$\left\\{\begin{array}{l}y=x+1 \\ y=3 x-1\end{array}\right.$$
4 step solution
Problem 20
Solve each system by the substitution method. If there is no solution or an infinite number of solutions, so state. Use set notation to express solution sets. $$\left\\{\begin{array}{l}2 x-y=4 \\\3 x-5 y=2\end{array}\right.$$
5 step solution
Problem 20
Graph the solution set of each system of linear inequalities. $$\left\\{\begin{array}{l}x+y \leq 4 \\\y \geq 2 x-4\end{array}\right.$$
4 step solution
Problem 21
In Exercises \(1-44,\) solve each system by the addition method. If there is no solution or an infinite number of solutions, so state. Use set notation to express solution sets. $$\left\\{\begin{array}{l} 3 x=2 y+7 \\ 5 x=2 y+13 \end{array}\right.$$
6 step solution
Problem 21
A community center sells a total of 301 tickets for a basketball game. An adult ticket costs 3 dollar A student ticket costs 1 dollar The sponsors collect 487 dollar in ticket sales. Find the number of each type of ticket sold.
5 step solution
Problem 21
Solve each system by graphing. If there is no solution or an infinite number of solutions, so state. Use set notation to express solution sets. $$\left\\{\begin{array}{l}y=2 x \\ y=-x+6\end{array}\right.$$
4 step solution