- The Five-Step Method
Inside Collection (Textbook): Basic Mathematics Review
Summary:
This module is from Elementary Algebra by Denny Burzynski and Wade Ellis, Jr. A detailed study of arithmetic operations with rational expressions is presented in this chapter, beginning with the definition of a rational expression and then proceeding immediately to a discussion of the domain. The process of reducing a rational expression and illustrations of multiplying, dividing, adding, and subtracting rational expressions are also included. Since the operations of addition and subtraction can cause the most difficulty, they are given particular attention. We have tried to make the written explanation of the examples clearer by using a "freeze frame" approach, which walks the student through the operation step by step. The five-step method of solving applied problems is included in this chapter to show the problem-solving approach to number problems, work problems, and geometry problems. The chapter also illustrates simplification of complex rational expressions, using the combine-divide method and the LCD-multiply-divide method. Objectives of this module: be able to use the five-step method to solve various applied problems.
We are now in a position to study some applications of rational equations. Some of these problems will have practical applications while others are intended as logic developers.
We will apply the five-step method for solving word problems.
Remember, step 1 is very important: always
Introduce a variable.
When the same number is added to the numerator and denominator of the fraction
Step 1: Let
The same number is added to the numerator and denominator of the fraction
Step 1: Let
Step 2:
Step 3:
Step 4:
Step 5: The number added is
.
The number added is 6.
Two thirds of a number added to the reciprocal of the number yields
Step 1: Let
Step 2: Recall that the reciprocal of a number
Step 4: Substituting into the original equation, it can be that both solutions check.
Step 5: There are two solutions:
Seven halves of a number added to the reciprocal of the number yields
Step 1: Let
Step 2:
Step 3:
Step 4:
Step 5: The number is
.
There are two numbers:
Person A, working alone, can pour a concrete walkway in 6 hours. Person B, working alone, can pour the same walkway in 4 hours. How long will it take both people to pour the concrete walkway working together?
Step 1: Let
Step 2: If person A can complete the job in 6 hours, A can complete
If person B can complete the job in 4 hours, B can complete
If A and B, working together, can complete the job in
Person A, working alone, can pour a concrete walkway in 9 hours. Person B, working alone, can pour the same walkway in 6 hours. How long will it take both people to pour the concrete walkway working together?
Step 1:
Step 2:
Step 3:
Step 4:
Step 5: Working together, A and B
.
Working together, A and B can pour the concrete walkway in
An inlet pipe can fill a water tank in 12 hours. An outlet pipe can drain the tank in 20 hours. If both pipes are open, how long will it take to fill the tank?
Step 1: Let
Step 2: If the inlet pipe can fill the tank in 12 hours, it can fill
If the outlet pipe can drain the tank in 20 hours, it can drain
If both pipes are open, it takes
Since water is being added (inlet pipe) and subtracted (outlet pipe) we get
An inlet pipe can fill a water tank in 8 hours and an outlet pipe can drain the tank in 10 hours. If both pipes are open, how long will it take to fill the tank?
Step 1:
Step 2:
Step 3:
Step 4:
Step 5:
It will take 40 hr to fill the tank.
It takes person A 3 hours longer than person B to complete a certain job. Working together, both can complete the job in 2 hours. How long does it take each person to complete the job working alone?
Step 1: Let
It takes person A 4 hours less than person B to complete a certain task. Working together, both can complete the task in
Step 1:
Step 2:
Step 3:
Step 4:
Step 5:
Person A, 4 hr to complete the task; person B, 8 hr complete the task.
The width of a rectangle is
Step 1: Let
Step 2: Make a sketch of the rectangle.
The perimeter of a figure is the total length around the figure.
The width of a rectangle is
Step 1:
Step 2:
Step 3:
Step 4:
Step 5:
length = 36 ft, width = 3 ft.
For the following problems, solve using the five-step method.
When the same number is added to both the numerator and denominator of the fraction
The number added is 5.
When the same number is added to both the numerator and denominator of the fraction
When the same number is added to both the numerator and denominator of the fraction
The number added is
When the same number is added to both the numerator and denominator of the fraction
When the same number is subtracted from both the numerator and denominator of
The number subtracted is
When the same number is subtracted from both the numerator and denominator of
One third of a number added to the reciprocal of number yields
Four fifths of a number added to the reciprocal of number yields
One half of a number added to twice the reciprocal of the number yields 2. What is the number?
2
One fourth of a number added to four times the reciprocal of the number yields
One inlet pipe can fill a tank in 8 hours. Another inlet pipe can fill the tank in 5 hours. How long does it take both pipes working together to fill the tank?
One pipe can drain a pool in 12 hours. Another pipe can drain the pool in 15 hours. How long does it take both pipes working together to drain the pool?
A faucet can fill a bathroom sink in 1 minute. The drain can empty the sink in 2 minutes. If both the faucet and drain are open, how long will it take to fill the sink?
two minutes
A faucet can fill a bathtub in
An inlet pipe can fill a tank in 5 hours. An outlet pipe can empty the tank in 4 hours. If both pipes are open, can the tank be filled? Explain.
No.
An inlet pipe can fill a tank in
A delivery boy, working alone, can deliver all his goods in 6 hours. Another delivery boy, working alone, can deliver the same goods in 5 hours. How long will it take the boys to deliver all the goods working together?
A Space Shuttle astronaut can perform a certain experiment in 2 hours. Another Space Shuttle astronaut who is not as familiar with the experiment can perform it in
One person can complete a task 8 hours sooner than another person. Working together, both people can perform the task in 3 hours. How many hours does it take each person to complete the task working alone?
First person: 12 hours; second person: 4 hours
Find two consecutive integers such that two thirds of the smaller number added to the other yields 11.
Find two consecutive integers such that three fourths of the smaller number added to the other yields 29.
The width of a rectangle is
The width of a rectangle is
Two sides of a triangle have the same length. The third side is twice as long as either of the other two sides. The perimeter of the triangle is 56 inches. What is the length of each side?
In a triangle, the second side is 3 inches longer than first side. The third side is
The pressure due to surface tension in a spherical drop of liquid is given by
(a) Determine the pressure due to surface tension within a soap bubble of radius 2 inches and surface tension 28.
(b) Determine the radius of a bubble if the pressure due to surface tension is 52 and the surface tension is 39.
The equation
(a) Determine the focal length of a lens in which an object 10 feet away produces an image 6 feet away.
(b) Determine how far an object is from a lens if the focal length of the lens is 6 inches and the image distance is 10 inches.
(c) Determine how far an image will be from a lens that has a focal length of
(a)
Person A can complete a task in 4 hours, person B can complete the task in 6 hours, and person C can complete the task in 3 hours. If all three people are working together, how long will it take to complete the task?
Three inlet pipes can fill a storage tank in 4, 6, and 8 hours, respectively. How long will it take all three pipes to fill the tank?
An inlet pipe can fill a tank in 10 hours. The tank has two drain pipes, each of which can empty the tank in 30 hours. If all three pipes are open, can the tank be filled? If so, how long will it take?
An inlet pipe can fill a tank in 4 hours. The tank has three drain pipes. Two of the drain pipes can empty the tank in 12 hours, and the third can empty the tank in 20 hours. If all four pipes are open, can the tank be filled? If so, how long will it take?
((Reference)) Factor
((Reference)) Find the slope of the line passing through the points
((Reference)) Find the quotient:
((Reference)) Find the difference:
0
((Reference)) Solve the equation
"Reviewer's Comments: 'I recommend this book for courses in elementary algebra. The chapters are fairly clear and comprehensible, making them quite readable. The authors do a particularly nice job […]"