Chapter 9

Elementary Algebra · 410 exercises

Problem 59

The area of a triangle is 14 square feet. If the base is 4 feet more than 2 times the height, then find the length of the base and the height.

7 step solution

Problem 60

Use the quadratic formula to solve the following. $$3 x_{2}+6 x+1=8$$

6 step solution

Problem 60

Solve using any method. $$ x(x-5)=12 $$

5 step solution

Problem 60

Solve using the quadratic formula. $$ x 2+2 x+9=0 $$

7 step solution

Problem 60

The area of a triangle is 8 square meters. If the base is 4 meters less than the height, then find the length of the base and the height.

8 step solution

Problem 61

Solve using any method. $$ (x+1)(x-8)+28=3 x $$

6 step solution

Problem 61

Solve by completing the square. $$3 x_{2}+2 x-2=0$$

8 step solution

Problem 61

Use the quadratic formula to solve the following. $$-2 y_{2}=3(y-1)$$

6 step solution

Problem 61

Solve using the quadratic formula. $$ y 2-6 y+17=0 $$

6 step solution

Problem 61

The perimeter of a rectangle is 54 centimeters and the area is 180 square centimeters. Find the dimensions of the rectangle.

8 step solution

Problem 61

Given the following quadratic functions, determine the domain and range. $$ f(x)=3 x 2+30 x+50 $$

5 step solution

Problem 62

Use the quadratic formula to solve the following. $$3 y_{2}=5(2 y-1)$$

6 step solution

Problem 62

Solve using any method. $$ (9 x-2)(x+4)=28 x-9 $$

5 step solution

Problem 62

Solve using the quadratic formula. $$ y 2-2 y+19=0 $$

6 step solution

Problem 62

Solve by extracting the roots. $$ 2(3 y-13) 2-52=0 $$

4 step solution

Problem 62

The perimeter of a rectangle is 50 inches and the area is 126 square inches. Find the dimensions of the rectangle.

12 step solution

Problem 62

Given the following quadratic functions, determine the domain and range. $$ f(x)=3 x 2+30 x+50 $$

5 step solution

Problem 63

Solve by completing the square. $$x(x+1)-11(x-2)=0$$

4 step solution

Problem 63

Set up an algebraic equation and use it to solve. The length of a rectangle is 2 inches less than twice the width. If the area measures 25 square inches, then find the dimensions of the rectangle. Round off to the nearest hundredth.

7 step solution

Problem 63

Use the quadratic formula to solve the following. $$(t+1) 2=2 t+7$$

2 step solution

Problem 63

Solve using the quadratic formula. $$ t 2-5 t+10=0 $$

5 step solution

Problem 63

Find a quadratic equation in standard form with the following solutions. $$ \pm 7 $$

4 step solution

Problem 63

George maintains a successful 6-meter-by-8-meter garden. Next season he plans on doubling the planting area by increasing the width and height by an equal amount. By how much must he increase the length and width?

8 step solution

Problem 64

Solve by completing the square. $$(x+1)(x+7)-4(3 x+2)=0$$

4 step solution

Problem 64

Use the quadratic formula to solve the following. $$(2 t-1) 2=73-4 t$$

4 step solution

Problem 64

Set up an algebraic equation and use it to solve. An 18-foot ladder leaning against a building reaches a height of 17 feet. How far is the base of the ladder from the wall? Round to the nearest tenth of a foot.

8 step solution

Problem 64

Solve using the quadratic formula. $$ t 2+3 t+4=0 $$

6 step solution

Problem 64

Find a quadratic equation in standard form with the following solutions. $$ \pm 13 $$

4 step solution

Problem 64

A uniform brick border is to be constructed around a 6 -foot-by-8-foot garden. If the total area of the garden, including the border, is to be 100 square feet, then find the width of the brick border. P

8 step solution

Problem 64

Given the following quadratic functions, determine the domain and range. $$ g(x)=-7 x 2-14 x-9 $$

4 step solution

Problem 65

Solve by completing the square. $$y 2=(2 y+3)(y-1)-2(y-1)$$

5 step solution

Problem 65

Use the quadratic formula to solve the following. $$(x+5)(x-1)=2 x+1$$

7 step solution

Problem 65

Set up an algebraic equation and use it to solve. The value in dollars of a new car is modeled by the function \(V(t)=125 t 2-3,000 t+22,000,\) where \(t\) represents the number of years since it was purchased. Determine the age of the car when its value is $$\$ 22,000$$.

5 step solution

Problem 66

Solve by completing the square. $$(2 y+5)(y-5)-y(y-8)=-24$$

5 step solution

Problem 66

Use the quadratic formula to solve the following. $$(x+7)(x-2)=3(x+1)$$

6 step solution

Problem 66

Set up an algebraic equation and use it to solve. The height in feet reached by a baseball tossed upward at a speed of 48 feet/second from the ground is given by the function \(h(t)=-16 t 2+48 t\), where \(t\) represents time in seconds. At what time will the baseball reach a height of 16 feet?

7 step solution

Problem 66

The height of a projectile launched straight up from a mound is given by the function \(h(t)=-16 t 2+96 t+4,\) where \(t\) represents seconds after launch. What is the maximum height?

4 step solution

Problem 67

Solve by completing the square. $$(t+2) 2=3(3 t+1)$$

6 step solution

Problem 67

Use the quadratic formula to solve the following. $$x(x+5)=3(x-1)$$

5 step solution

Problem 67

Determine the x- and y-intercepts. $$ y=2 x 2+5 x-3 $$

5 step solution

Problem 67

Solve using the quadratic formula. $$ -y 2-y-2=0 $$

5 step solution

Problem 67

The profit in dollars generated by producing and selling \(x\) custom lamps is given by the function \(P(x)=-10 x_{2}+800 x-12,000 .\) What is the maximum profit?

4 step solution

Problem 68

Solve by completing the square. $$(3 t+2)(t-4)-(t-8)=1-10 t$$

5 step solution

Problem 68

Use the quadratic formula to solve the following. $$x(x+4)=-7$$

7 step solution

Problem 68

Determine the x- and y-intercepts. $$ y=x 2-12 $$

2 step solution

Problem 68

The revenue in dollars generated from selling a particular item is modeled by the formula \(R(x)=100 x-0.0025 x_{2},\) where \(x\) represents the number of units sold. What number of units must be sold to maximize revenue?

4 step solution

Problem 69

Use the quadratic formula to solve the following. $$(5 x+3)(5 x-3)-10(x-1)=0$$

7 step solution

Problem 69

Solve by completing the square and round off the solutions to the nearest hundredth. $$(2 x-1) 2=2 x$$

7 step solution

Problem 69

Solve using the quadratic formula. $$ -2 x_{2}+10 x-17=0 $$

6 step solution

Problem 69

The top of a 20-foot ladder, leaning against a building, reaches a height of 18 feet. How far is the base of the ladder from the wall? Round off to the nearest hundredth.

5 step solution

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