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

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