Algebra: Chapter 10, Lesson 7, page 455.
Using Rational Equations
We are working on DRT problems and “WORK” `1/x` problems. These say, if it takes one person 2 hours to do a job and another person 3 hours, how long does it take them both, working together to do the job.
Here is a link for DRT problems and here is a link for these work type of problems.
Remember, for the work problems, think of setting up the problem on a per hour basis. For example, if it takes one person 3 hours to paint a wall and another 5 hours, then in 1 hour, each person can do `1/3` and `1/5` of the project. If you put them together, then it would take `t` time, BUT, if you only worry about `1` hours’ worth with both working together, then in `1` hour they can both do `1/t` of the project.
Adding this up, we would get an equation that looks like:
`1/3 + 1/5 = 1/t`
You know how to solve that by first finding the LCM (in this example it is `3⋅5⋅t` or `15t`)
Two of tonight’s homework problems solved by MrE are here! Just click it!
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Algebra 1a: Chapter 8, Lesson 4, page 373.
Using systems of equations
Steps to solve systems of equations can be:
- Graph the equations
- Substitution of one variable in terms of the other
- Adding or subtracting the 2 equations
Before you start attacking the word problem, make sure you have a plan of attack such as:
- Understand the problem
- Develop and carry out a PLAN
- Find the ANSWER and CHECK
Click here for a pretty good link from purplemath.com with examples.
Two of tonight’s homework problems solved by MrE are here! Just click it!