Try, Check, and Revise and Work Backward

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Try, Check, and Revise and Work Backward
COURSE 2 LESSON 4-7
Kayla is bringing brownies to the sports
banquet. She needs to be there by 715 P.M. It
will take Kaylas family h to walk from their
apartment to school. The brownies take hour to
make, hour to bake, and 1 hours to cool.
What is the latest time Kayla can start making
the brownies so they will be cool before she
leaves for the banquet?
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1 4
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Try, Check, and Revise and Work Backward
COURSE 2 LESSON 4-7
(continued)
Starting the brownies at 530 P.M. causes Kayla
to arrive 45 min later than intended. Therefore,
by starting the brownies 45 min earlier, at 445
P.M. , Kayla will arrive at 715 P.M.
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Try, Check, and Revise and Work Backward
COURSE 2 LESSON 4-7
(continued)
Method 2  Work Backward
You know that the series of events must end at
715 P.M. It makes sense to work backward to
find when Kayla must start making the brownies.
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Try, Check, and Revise and Work Backward
COURSE 2 LESSON 4-7
(continued)
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Try, Check, and Revise and Work Backward
COURSE 2 LESSON 4-7
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You need to be in school at 745 A.M. It takes
you h to shower and brush your teeth, 10 min
to get dressed, and 20 min to eat breakfast. The
bus, which picks you up outside your house, takes
h to get to school. What is the latest
time you should get up in the morning?
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600 A.M.
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