Elementary Algebra
Introduction to Algebra Linear Equations and Inequalities Functions and Graphs I Lines and thier Graphs Linear Systems Exponents & Polynomials
Intermediate Algebra
Factoring Rational Expressions Rational Equations and Applications Radical Expressions Nonlinear Equations and Applications Functions and Graphs II Exponential and Logarithmic Functions
Precalculus I / College Algebra
Equations and Inequalitites Functions and Graphs Polynomial and Rational Functions Exponential and Logarithmic Functions Systems and Matrices Geometry Basics Conic Sections Sequences and Series
Precalculus II / Trigonometry
The Six Trigonometric Functions Right Triangle Trigonometry Circular Functions Graphs of Trigonometric Functions Trigonometric Identities Trigonometric Equations Oblique Triangles and the Laws Vectors Complex, Parametric, and Polar Forms
Calculus I
Limits and Continuity Derivatives Analysis of Curves Antiderivatives
Calculus II
Transcendental Functions
Geometry Physics Integration Techniques Calculus of Infinity Parametric, Polar, and Conic Curves
Calculus III

Course: Intermediate Algebra
Topic: Rational Equations and Applications
Subtopic: Applications - Work & Motion

Overview

Today we are going to apply our knowledge of solving rational equations to two types of word problems. We cover work problems where people or machines are working and motion problems where people or machines are moving. Organizing the information into a chart is recommended. Once you are able to form an equation it will likely be rational in nature solvable by the LCD or cross-products method we recently studied.

Objectives

By the end of this topic you should know and be prepared to be tested on:

• 9.3.1 Solve word problems involving proportions
• 9.3.2 Solve word problems involving work (e.g., painters, plumbers, copy machines)
• 9.3.3 Solve word problems involving motion (e.g., cars, bikes, trains, planes, boats)
• 9.3.4 Solve motion problems involving currents (e.g., headwinds, river currents)

Terminology

Terms you should be able to define: rate, memorize the distance=rate*time formula D=RT

Text Notes

Concentrate mostly on the work and motion types of word problems in this section. Also be prepared to be tested on the proportion types which are readily solved by the cross-products method.

If your text contains any "similar triangles" problems you may SKIP them as this material is covered in a pre-calculus class.

Supplementary Resources

Translating and solving word problems is often a sticking point for students, but if you keep an optimistic attitude, take one step at a time, and read the problem carefully, you can do it! Here are some useful resources:

• Mildred Johnson wrote an excellent little book that covers solving several different types of word problems in a manner similar to that we do here. It is available in print, but most of it is available free online in Google books How to Solve Word Problems in Algebra, 2nd ed. Start at page 19 for motion problems and at page 123 for work problems.

• PurpleMath.com is always recommended! See Motion Problems and Work Problems.