2. Algebra 2 4.2, 4.3a Machhapuchhare

3. SAT Question: When it is 7:00 am in Seattle, it is 10:00 am in Philadelphia. A plane is scheduled to leave Philadelphia at 11:30 am (Philadelphia time) and to arrive in Seattle at 4:15 pm (Seattle time). How many hours are scheduled for the trip? A. B. C. D. E. 11:30 to 4:15 is 4 ¾ hours. Add three hours for the time change. E is the answer.

4. The substitution method is best to use when one equation is solved for one of the variables, or when one equation has a variable with a coefficient of 1.

5. Example 2

6. Example 3

7. The linear combination method works best when both equations are in the form Ax + By = C, and especially when none of the variables have a coefficient of 1. We use the properties of addition and multiplication to solve using linear combinations. Steps: 1.Write both equations in the form Ax + By = C 2.Clear fractions or decimals. 3.Choose a variable to eliminate. 4.Eliminate the variable by multiplying by an appropriate number to make the two variables add to zero; then add the equations together. 5.Check by substituting answer into original equations.

8. Example 1:

9. Example 2:

10. Example 3:

11. Example 4:

12. Example 5:

15. Example of simple word problem: Eight small boxes plus 5 large boxes cost $184. A large box costs $3.00 more than a small box. What is the cost of each size of box? x = small box y = large box $13 for small box; $16 for large box

16. Classwork: 2, 10, 14, 18, 22/166; 2/171

17. Get ready for a “Small Quiz” to be written on your grade sheet.

18. THE END

19. Quiz. Copy the problems and write the answer. Put your grade paper on the front of your row, quiz side down. Find the solution by graphing: