Chapter 5
Beginning and Intermediate Algebra · 277 exercises
Problem 21
Solve each system by substitution. $$\begin{aligned}&2 x-y=6\\\&3 y=-18-x\end{aligned}$$
5 step solution
Problem 22
Solve each systen \(\begin{aligned}-3 a+5 b+c &=-4 \\ a+5 b &=3 \\ 4 a-3 c &=-11 \end{aligned}\)
7 step solution
Problem 22
Graph each equation by finding the intercepts and at least ne ether point. $$y=-3$$
3 step solution
Problem 22
Solve each system using the elimination method. $$\begin{aligned}&4+9 y=-21 x\\\&14 x+6 y=-1\end{aligned}$$
10 step solution
Problem 22
Solve each system by substitution. $$\begin{aligned}&y-4 x=-1\\\&8 x+y=2\end{aligned}$$
5 step solution
Problem 22
Write a system of equations and solve. Assume two families pay the average ticket price to attend a Green Bay Packers game in 2004 . One family buys four tickets and a parking pass for \(\$ 242.60 .\) The other family buys six tickets and a parking pass for \(\$ 351.40 .\) Find the average ticket price and the cost of a parking pass to a Packers game in 2004
2 step solution
Problem 23
Write a system of equations and solve. On vacation, Wendell buys three key chains and five postcards for \(\$ 10.00,\) and his sister buys two key chains and three postcards for \(\$ 6.50 .\) Find the cost of each souvenir.
5 step solution
Problem 23
Solve each systen \(\begin{aligned}-5 x+z &=-3 \\ 4 x-y &=-1 \\ 3 y-7 z &=1 \end{aligned}\)
6 step solution
Problem 23
Solve each system using the elimination method. $$\begin{aligned}&9 x-7 y=-14\\\&4 x+3 y=6\end{aligned}$$
6 step solution
Problem 23
Solve each system by substitution. $$\begin{aligned}&2 x-5 y=-4\\\&8 x-9 y=6\end{aligned}$$
6 step solution
Problem 24
Write a system of equations and solve. At Sparkle Car Wash, two deluxe car washes and three regular car washes would cost \(\$ 26.00 .\) Four regular washes and one deluxe wash would cost \(\$ 23.00 .\) What is the cost of a deluxe car wash and of a regular wash? (THE IMAGES CANNOT COPY)
4 step solution
Problem 24
Solve each systen \(a+b=1\) \(a-5 c=2\) \(b+2 c=-4\)
9 step solution
Problem 24
Solve each system using the elimination method. $$\begin{aligned}&6 x+5 y=13\\\&5 x+3 y=5\end{aligned}$$
6 step solution
Problem 24
Solve each system by substitution. $$\begin{aligned}&2 x+3 y=6\\\&5 x+2 y=-7\end{aligned}$$
6 step solution
Problem 25
Solve each systen \(\begin{aligned} 4 a+2 b &=-11 \\\\-8 a-3 c &=-7 \\ b+2 c &=1 \end{aligned}\)
7 step solution
Problem 25
Use the slope formula to find the slope of the line containing each pair of points. $$(1,7) \text { and }(-4,2)$$
4 step solution
Problem 25
What is the first step in solving this system by the elimination method? Do not solve. $$\begin{aligned}0.1 x+2 y &=-0.8 \\\0.03 x+0.10 y &=0.26\end{aligned}$$
2 step solution
Problem 25
Solve each system by substitution. $$\begin{aligned}&9 y-2 x=22\\\&4 x+6 y=-12\end{aligned}$$
5 step solution
Problem 25
Write a system of equations and solve. Ella spends \(\$ 7.50\) on three cantaloupe and one watermelon at a farmers' market. Two cantaloupe and two watermelon would have cost \(\$ 9.00 .\) What is the price of a cantaloupe and the price of a watermelon?
4 step solution
Problem 26
Write a system of equations and solve. One 12 -oz serving of Coke and two 12 -oz servings of Mountain Dew contain 31.3 tsp of sugar while three servings of Coke and one Mountain Dew contain 38.9 tsp of sugar. How much sugar is in a \(12-0 \mathrm{Z}\) serving of each drink? (Source; wwwdentalgentlecare com)
3 step solution
Problem 26
Solve each systen \(3 x+4 y=-6\) \(-x+3 z=1\) \(2 y+3 z=-1\)
3 step solution
Problem 26
Use the slope formula to find the slope of the line containing each pair of points. $$(-2,-3) \text { and }(3,-1)$$
3 step solution
Problem 26
What is the first step in solving this system by the elimination method? Do not solve. $$\begin{aligned}&\frac{x}{4}+\frac{y}{2}=-1\\\&\frac{3}{8} x+\frac{5}{3} y=-\frac{7}{12}\end{aligned}$$
2 step solution
Problem 26
Solve each system by substitution. $$\begin{aligned}&12 x-9 y=-8\\\&-6 x+5 y=5\end{aligned}$$
5 step solution
Problem 27
Write a system of equations and solve. Carol orders six White Castle hamburgers and a small order of fries for \(\$ 3.91,\) and Momar orders eight hamburgers and two small fries for \(\$ 5.94 .\) Find the cost of a hamburger and the cost of an order of french fries at White Castle, (Source: White Castle menu)
5 step solution
Problem 27
Solve each system \(\begin{aligned} 6 x+3 y-3 z &=-1 \\ 10 x+5 y-5 z &=4 \\ x-3 y+4 z &=6 \end{aligned}\)
2 step solution
Problem 27
Use the slope formula to find the slope of the line containing each pair of points. $$(-2,5) \text { and }(3,-8)$$
4 step solution
Problem 27
Solve each system using the elimination method. $$\begin{aligned}\frac{x}{4}+\frac{y}{2} &=-1 \\\\\frac{3}{8} x+\frac{5}{3} y &=-\frac{7}{12}\end{aligned}$$
5 step solution
Problem 28
Write a system of equations and solve. Six White Castle hamburgers and one small order of french fries contain 955 calories. Eight hamburgers and two orders of fries contain \(1350 .\) Determine how many calories are in a White Castle hamburger and in a small order of french fries. (Source: www.whitecastle com)
2 step solution
Problem 28
Solve each system \(\begin{aligned} 2 x+3 y-z &=0 \\ x-4 y-2 z &=-5 \\\\-4 x+5 y+3 z &=-4 \end{aligned}\)
4 step solution
Problem 28
Use the slope formula to find the slope of the line containing each pair of points. $$(0,4) \text { and }(8,-2)$$
4 step solution
Problem 28
Solve each system using the elimination method. $$\begin{aligned}&\frac{1}{2} x+\frac{2}{3} y=-\frac{29}{6}\\\&-\frac{1}{3} x+y=-4\end{aligned}$$
5 step solution
Problem 28
Solve each system by substitution. $$\begin{aligned}28 x+7 y &=1 \\\4 x+y &=-6\end{aligned}$$
5 step solution
Problem 29
Write a system of equations and solve. How many ounces of a \(9 \%\) alcohol solution and how many ounces of a \(17 \%\) alcohol solution must be mixed to get 12 oz of a \(15 \%\) alcohol solution?
5 step solution
Problem 29
Solve each system \(\begin{aligned} 7 x+8 y-z &=16 \\\\-\frac{1}{2} x-2 y+\frac{3}{2} z &=1 \\\ \frac{4}{3} x+4 y-3 z &=-\frac{2}{3} \end{aligned}\)
6 step solution
Problem 29
Use the slope formula to find the slope of the line containing each pair of points. $$\left(\frac{3}{2},-1\right) \text { and }\left(-\frac{5}{2}, 7\right)$$
4 step solution
Problem 29
Solve each system using the elimination method. $$\begin{aligned}&\frac{x}{2}-\frac{y}{5}=\frac{1}{10}\\\&\frac{x}{3}+\frac{y}{4}=\frac{5}{6}\end{aligned}$$
5 step solution
Problem 29
If an equation in a system contains fractions, what should you do first to make the system easier to solve?
5 step solution
Problem 30
Write a system of equations and solve. How many milliliters of a \(4 \%\) acid solution and how many milliliters of a \(10 \%\) acid solution must be mixed to obtain \(54 \mathrm{ml}\) of a \(6 \%\) acid solution?
5 step solution
Problem 30
Solve each system \(\begin{aligned} 3 a+b-2 c &=-3 \\ 9 a+3 b-6 c &=-9 \\\\-6 a-2 b+4 c &=6 \end{aligned}\)
3 step solution
Problem 30
Use the slope formula to find the slope of the line containing each pair of points. $$(2.5,5.3) \text { and }(-3.5,-1.9)$$
5 step solution
Problem 30
Solve each system using the elimination method. $$\begin{array}{r}x+\frac{y}{4}=\frac{7}{2} \\\\\frac{2}{5} x+\frac{1}{2} y=-1\end{array}$$
6 step solution
Problem 30
If an equation in a system contains decimals, what should you do first to make the system easier to solve?
4 step solution
Problem 31
Solve each system \(\begin{aligned} 2 a-3 b &=-4 \\ 3 b-c &=8 \\\\-5 a+4 c &=-4 \end{aligned}\)
8 step solution
Problem 31
Use the slope formula to find the slope of the line containing each pair of points. $$(9,0) \text { and }(9,4)$$
4 step solution
Problem 31
Solve each system using the elimination method. $$\begin{aligned}x+\frac{3}{2} y &=13 \\\\-\frac{1}{8} x+\frac{1}{4} y &=\frac{1}{8}\end{aligned}$$
6 step solution
Problem 31
Solve each system by substitution. $$\begin{aligned}&\frac{1}{4} x-\frac{1}{2} y=1\\\&\frac{2}{3} x+\frac{1}{6} y=\frac{25}{6}\end{aligned}$$
5 step solution
Problem 32
\(\begin{aligned} 5 x+y-2 z &=-2 \\\\-\frac{1}{2} x-\frac{3}{4} y+2 z &=\frac{5}{4} \\ x-6 z &=3 \end{aligned}\)
5 step solution
Problem 32
Use the slope formula to find the slope of the line containing each pair of points. $$(-7,4) \text { and }(1,4)$$
5 step solution
Problem 32
Solve each system using the elimination method. $$\begin{array}{l}\frac{x}{12}-\frac{y}{6}=\frac{2}{3} \\\\\frac{x}{4}+\frac{y}{3}=2\end{array}$$
6 step solution