Name_______________________________Date____________Period______
THE SUBSTITUTION METHOD
Today Rita sold twice as many bags of chips at the basketball game as she sold last Friday.
In the 2 days she sold a total of 141 bags. Write and solve a system of equations that will
determine the number of bags Rita sold last Friday and the number of bags she sold today?
1. What are the two things we are trying to find in this problem?
2. Independent Variable?
3. Dependent Variable?
4. Make a table to guess and check
X
5. Explain how you found out how many bags of chips Rita sold today?
SATEC/Algebra I/Linear Systems/401289554/Rev.07-01
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6. How did you get the total number of bags sold on the two days?
7. Write an equation for the number of bags sold today.
8. Write an equation for the number of bags sold Friday.
9. Solve this system of equations using substitution.
10. What is the solution to this equation?
(
,
)
11. Graph these two equations in your calculator. Where do they intersect?
(
,
)
12. What do the coordinates of this point mean?
SATEC/Algebra I/Linear Systems/401289554/Rev.07-01
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