1. 10-7 Using Rational Equations
Standard 15.0: Apply algebraic techniques to rate and work problems.

2. Vocabulary Problem-Solving Guidelines UNDERSTAND the problem
Develop and carry out a PLAN
Find the ANSWER and CHECK

3. #1 Solving Work Problems
A contractor finds that it takes Crew A 6 hours to construct a wall of a certain size. Crew B takes 8 hours to construct a wall of the same size. How long will it take if they work together?
Let x = the total number of hours to complete the job.

4. #1 Solving Work Problems
Working Together

5. #1 Solving Work Problems

6. #2 Solving Motion Problems
One boat travels 10 km/h faster than another. While one boat travels 120 km, the other travels 155 km. Find their speeds.
Let t = time each boat traveled.

7. #2 Solving Motion Problems
Distance
Rate
Time
SlowBoat
120 r t
Fast Boat
155
r + 10 t
Solve both equations for t

8. #2 Solving Motion Problems
Substitute the first equation for t

9. #3 Solving Number Problems
The reciprocal of two more than a number is three times the reciprocal of the number. Find the number.

10. #3 Solving Number Problems