Chapter 1
College Algebra Essentials · 725 exercises
Problem 151
Determine whether each statement is true or false. If the statement is false, make the necessary change(s) to produce a true statement . $$(-\infty, 3) \cup(-\infty,-2)=(-\infty,-2)$$
4 step solution
Problem 152
A machine produces open boxes using square sheets of metal. The machine cuts equal-sized squares measuring 3 inches on a side from the corners and then shapes the metal into an open box by turning up the sides. If each box must have a volume of 75 cubic inches, find the length and width of the open box.
4 step solution
Problem 154
A piece of wire is 8 inches long. The wire is cut into two pieces and then each piece is bent into a square. Find the length of each piece if the sum of the areas of these squares is to be 2 square inches.
4 step solution
Problem 154
What's wrong with this argument? Suppose \(x\) and \(y\) represent two real numbers, where \(x>y\). \(2>1 \quad\) This is a true statement \(2(y-x)>1(y-x) \quad\) Multiply both sides by \(y-x\) \(2 y-2 x>y-x \quad\) Use the distributive property. \(y-2 x>-x \quad\) Subtract \(y\) from both sides. \(y>x \quad\) Add \(2 x\) to both sides. The final inequality, \(y>x,\) is impossible because we were initially given \(x>y\).
4 step solution
Problem 155
What is a quadratic equation?
3 step solution
Problem 156
Explain how to solve \(x^{2}+6 x+8=0\) using factoring and the zero-product principle.
3 step solution
Problem 156
Each group member should research one situation that provides two different pricing options. These can involve areas such as public transportation options (with or without discount passes), cellphone plans, long-distance telephone plans, or anything of interest. Be sure to bring in all the details for each option. At a second group meeting, select the two pricing situations that are most interesting and relevant. Using each situation, write a word problem about selecting the better of the two options. The word problem should be one that can be solved using a linear inequality. The group should turn in the two problems and their solutions.
4 step solution
Problem 157
Explain how to solve \(x^{2}+6 x+8=0\) by completing the square.
3 step solution
Problem 157
Here are two sets of ordered pairs: $$ \begin{aligned} &\operatorname{set} 1:\\{(1,5),(2,5)\\}\\\ &\operatorname{set} 2:\\{(5,1),(5,2)\\} \end{aligned} $$ In which set is each \(x\) -coordinate paired with only one \(y\)-coordinate?
3 step solution
Problem 158
Explain how to solve \(x^{2}+6 x+8=0\) using the quadratic formula.
5 step solution
Problem 158
Graph \(y=2 x\) and \(y-2 x+4\) in the same rectangular coordinate system. Select integers for \(x,\) starting with \(-2\) and ending with 2.
2 step solution
Problem 159
How is the quadratic formula derived?
5 step solution
Problem 160
What is the discriminant and what information does it provide about a quadratic equation?
2 step solution
Problem 161
If you are given a quadratic equation, how do you determine which method to use to solve it?
3 step solution
Problem 162
Describe the relationship between the real solutions of \(a x^{2}+b x+c=0\) and the graph of \(y=a x^{2}+b x+c\).
3 step solution
Problem 163
If a quadratic equation has imaginary solutions, how is this shown on the graph of \(y=a x^{2}+b x+c ?\)
3 step solution
Problem 166
In Exercises \(166-169\), determine whether each statement makes sense or does not make sense, and explain your reasoning. Because I want to solve \(25 x^{2}-169=0\) fairly quickly, I'll use the quadratic formula.
4 step solution
Problem 168
In Exercises \(166-169\), determine whether each statement makes sense or does not make sense, and explain your reasoning. I obtained \(-17\) for the discriminant, so there are two imaginary irrational solutions.
3 step solution
Problem 171
In Exercises \(170-173\), determine whether each statement is true or false. If the statement is false, make the necessary change(s) to produce a true statement. Any quadratic equation that can be solved by completing the square can be solved by the quadratic formula.
4 step solution
Problem 174
Write a quadratic equation in general form whose solution set is \(\\{-3,5\\}\).
4 step solution
Problem 175
Solve for \(t: s=-16 t^{2}+v_{0} t\)
3 step solution
Problem 176
A rectangular swimming pool is 12 meters long and 8 meters wide. A tile border of uniform width is to be built around the pool using 120 square meters of tile. The tile is from a discontinued stock (so no additional materials are available) and all 120 square meters are to be used. How wide should the border be? Round to the nearest tenth of a meter. If zoning laws require at least a 2 -meter-wide border around the pool, can this be done with the available tile?
5 step solution
Problem 177
Exercises \(177-179\) will help you prepare for the material covered in the next section. Factor completely: \(x^{3}+x^{2}-4 x-4\)
4 step solution
Problem 178
Exercises \(177-179\) will help you prepare for the material covered in the next section. Use the special product \((A+B)^{2}=A^{2}+2 A B+B^{2}\) to multiply: \((\sqrt{x+4}+1)^{2}\)
3 step solution
Problem 179
Exercises \(177-179\) will help you prepare for the material covered in the next section. If \(-8\) is substituted for \(x\) in the equation \(5 x^{\frac{2}{3}}+11 x^{\frac{1}{3}}+2=0\) is the resulting statement true or false?
3 step solution