Chapter 10
Elementary Algebra · 172 exercises
Problem 124
Solve by using the Quadratic Formula. \(3 t(t-2)=2\)
6 step solution
Problem 126
Solve by using the Quadratic Formula. \(4 d^{2}-7 d+2=0\)
4 step solution
Problem 128
Solve by using the Quadratic Formula. \(\frac{1}{9} c^{2}+\frac{2}{3} c=3\)
6 step solution
Problem 129
Solve by using the Quadratic Formula. \(2 x^{2}+12 x-3=0\)
7 step solution
Problem 130
Solve by using the Quadratic Formula. \(16 y^{2}+8 y+1=0\)
5 step solution
Problem 132
Determine the number of solutions to each quadratic equation. (a) \(9 v^{2}-15 v+25=0\) \(100 w^{2}+60 w+9=0\) \(5 c^{2}+7 c-10=0\) \(15 d^{2}-4 d+8=0\)
9 step solution
Problem 133
Determine the number of solutions to each quadratic equation. (a) \(r^{2}+12 r+36=0\) \(8 t^{2}-11 t+5=0\) \(4 u^{2}-12 u+9=0\) \(3 v^{2}-5 v-1=0\)
8 step solution
Problem 134
In the following exercises, determine the number of solutions to each quadratic equation. a. \(25 p^{2}+10 p+1=0\) b.\(7 q^{2}-3 q-6=0\) c.\(7 y^{2}+2 y+8=0\) d.\(25 z^{2}-60 z+36=0\)
3 step solution
Problem 135
In the following exercises, identify the most appropriate method (Factoring, Square Root, or Quadratic Formula) to use to solve each quadratic equation. Do not solve. (a) \(x^{2}-5 x-24=0\) (b)\((y+5)^{2}=12\) (c)\(14 m^{2}+3 m=11\)
4 step solution
Problem 136
In the following exercises, identify the most appropriate method (Factoring, Square Root, or Quadratic Formula) to use to solve each quadratic equation. Do not solve. (a)\((8 v+3)^{2}=81\) (b)\(w^{2}-9 w-22=0\) (c)\(4 n^{2}-10=6\)
4 step solution
Problem 137
In the following exercises, identify the most appropriate method (Factoring, Square Root, or Quadratic Formula) to use to solve each quadratic equation. Do not solve. (a) \(6 a^{2}+14=20\) (b) \(\left(x-\frac{1}{4}\right)^{2}=\frac{5}{16}\) (c) \(y^{2}-2 y=8\)
3 step solution
Problem 138
In the following exercises, identify the most appropriate method (Factoring, Square Root, or Quadratic Formula) to use to solve each quadratic equation. Do not solve. (a) \(8 b^{2}+15 b=4\) (b) \(\frac{5}{9} v^{2}-\frac{2}{3} v=1\) (c) \(\left(w+\frac{4}{3}\right)^{2}=\frac{2}{9}\)
3 step solution
Problem 139
A flare is fired straight up from a ship at sea. Solve the equation \(16\left(t^{2}-13 t+40\right)=0\) for \(t,\) the number of seconds it will take for the flare to be at an altitude of 640 feet.
6 step solution
Problem 140
An architect is designing a hotel lobby. She wants to have a triangular window looking out to an atrium, with the width of the window 6 feet more than the height. Due to energy restrictions, the area of the window must be 140 square feet. Solve the equation \(\frac{1}{2} h^{2}+3 h=140\) for \(h,\) the height of the window.
6 step solution
Problem 141
Solve the equation \(x^{2}+10 x=200\) by completing the square (b) using the Quadratic Formula (c) Which method do you prefer? Why?
6 step solution
Problem 142
Solve the equation \(12 y^{2}+23 y=24\) (a) by completing the square (b) using the Quadratic Formula ( Which method do you prefer? Why?
6 step solution
Problem 143
The product of two consecutive odd numbers is 255 . Find the numbers.
7 step solution
Problem 145
The product of two consecutive even numbers is 624 . Find the numbers.
7 step solution
Problem 146
The product of two consecutive odd numbers is \(1023 .\) Find the numbers.
7 step solution
Problem 147
The product of two consecutive odd numbers is \(483 .\) Find the numbers.
8 step solution
Problem 148
The product of two consecutive even numbers is 528 . Find the numbers.
8 step solution
Problem 150
The width of a triangle is six more than twice the height. The area of the triangle is 88 square yards. Find the height and width of the triangle.
7 step solution
Problem 151
The hypotenuse of a right triangle is twice the length of one of its legs. The length of the other leg is three feet. Find the lengths of the three sides of the triangle. Round to the nearest tenth.
6 step solution
Problem 152
The hypotenuse of a right triangle is \(10 \mathrm{~cm}\) long. One of the triangle's legs is three times the length of the other leg. Find the lengths of the three sides of the triangle. Round to the nearest tenth.
6 step solution
Problem 153
A farmer plans to fence off sections of a rectangular corral. The diagonal distance from one corner of the corral to the opposite corner is five yards longer than the width of the corral. The length of the corral is three times the width. Find the length of the diagonal of the corral. Round to the nearest tenth.
8 step solution
Problem 155
The length of a rectangular driveway is five feet more than three times the width. The area is 350 square feet. Find the length and width of the driveway.
5 step solution
Problem 156
A rectangular lawn has area 140 square yards. Its width that is six less than twice the length. What are the length and width of the lawn?
6 step solution
Problem 157
A firework rocket is shot upward at a rate of \(640 \mathrm{ft} / \mathrm{sec}\). Use the \(\quad\) projectile formula \(h=-16 t^{2}+v_{0} t\) to determine when the height of the firework rocket will be 1200 feet.
8 step solution
Problem 158
An arrow is shot vertically upward at a rate of 220 feet per second. Use the projectile formula \(h=-16 t^{2}+v_{0} t\) to determine when height of the arrow will be 400 feet.
7 step solution
Problem 159
A bullet is fired straight up from a BB gun with initial velocity 1120 feet per second at an initial height of 8 feet. Use the formula \(h=-16 t^{2}+v_{0} t+8\) to determine how many seconds it will take for the bullet to hit the ground. (That is, when will \(h=0\) ?)
6 step solution
Problem 160
A city planner wants to build a bridge across a lake in a park. To find the length of the bridge, he makes a right triangle with one leg and the hypotenuse on land and the bridge as the other leg. The length of the hypotenuse is 340 feet and the leg is 160 feet. Find the length of the bridge.
5 step solution
Problem 161
Make up a problem involving the product of two consecutive odd integers. Start by choosing two consecutive odd integers. (a) What are your integers? (b) What is the product of your integers? (c) Solve the equation \(n(n+2)=p,\) where \(p\) is the product you found in part (b). (1) Did you get the numbers you started with?
8 step solution
Problem 162
Make up a problem involving the product of two consecutive even integers. Start by choosing two consecutive even integers. (a) What are your integers? (b) What is the product of your integers? (c) Solve the equation \(n(n+2)=p,\) where \(p\) is the product you found in part (b). (d) Did you get the numbers you started with?
5 step solution
Problem 163
Recognize the Graph of a Quadratic Equation in Two Variables. $$ y=x^{2}+3 $$
5 step solution
Problem 164
Recognize the Graph of a Quadratic Equation in Two Variables. $$ y=-x^{2}+1 $$
6 step solution
Problem 165
In the following exercises, determine if the parabola opens up or down. $$ y=-2 x^{2}-6 x-7 $$
3 step solution
Problem 166
In the following exercises, determine if the parabola opens up or down. $$ y=6 x^{2}+2 x+3 $$
3 step solution
Problem 167
In the following exercises, determine if the parabola opens up or down. $$ y=4 x^{2}+x-4 $$
3 step solution
Problem 168
In the following exercises, determine if the parabola opens up or down. $$ y=-9 x^{2}-24 x-16 $$
3 step solution
Problem 169
In the following exercises, find (a) the axis of symmetry and (b) the vertex. $$ y=x^{2}+8 x-1 $$
3 step solution
Problem 170
In the following exercises, find (a) the axis of symmetry and (b) the vertex. $$ y=x^{2}+10 x+25 $$
3 step solution
Problem 171
In the following exercises, find (a) the axis of symmetry and (b) the vertex. $$ y=-x^{2}+2 x+5 $$
3 step solution
Problem 172
In the following exercises, find (a) the axis of symmetry and (b) the vertex. $$ y=-2 x^{2}-8 x-3 $$
3 step solution
Problem 174
In the following exercises, find the \(x\) - and \(y\) -intercepts. $$ y=x^{2}+10 x-11 $$
4 step solution
Problem 175
In the following exercises, find the \(x\) - and \(y\) -intercepts. $$ y=-x^{2}+8 x-19 $$
5 step solution
Problem 176
In the following exercises, find the \(x\) - and \(y\) -intercepts. $$ y=x^{2}+6 x+13 $$
4 step solution
Problem 177
In the following exercises, find the \(x\) - and \(y\) -intercepts. $$ y=4 x^{2}-20 x+25 $$
4 step solution
Problem 178
In the following exercises, find the \(x\) - and \(y\) -intercepts. $$ y=-x^{2}-14 x-49 $$
4 step solution
Problem 179
In the following exercises, graph by using intercepts, the vertex, and the axis of symmetry. $$ y=x^{2}+6 x+5 $$
5 step solution
Problem 180
In the following exercises, graph by using intercepts, the vertex, and the axis of symmetry. $$ y=x^{2}+4 x-12 $$
6 step solution