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