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Name Chapter 9, Lesson 3 Reteach Date Write Function Rules Using Two Variables CA Standards AF 1.5, AF 1.1 You will write the rule for the function table. Rule: ? Input (a) Output (b) 2 1 4 2 6 3 8 4 10 5 Step 1 Look at the table carefully. Note that b stands for the output, and a stands for the input. You are trying to find the value of b. Begin to write the function rule by placing b on one side of an equal sign. b= Step 2 Look at the first row of the table. Think about how the input value and the output value are related. There are two ways to get an output value of 1 when the input value is 2. One method is subtracting 1 from a. The other method is dividing a by 2. Since there are two possible choices, you need to read further in the chart to find a pattern. Step 3 Repeat the process for the second row. To get an output value of 2 when the input value is 4, you could subtract 2 from a. The other method is dividing a by 2. Since dividing a by 2 works for both rows, this is the rule for the function table. Write the rule in an equation with two variables. Solution: The rule for this table is b = a ÷ 2. Write the rule for each function table. 1. Rule: 2. Rule: 3. Rule: Input (a) Output (b) Input (a) Output (b) Input (m) Output (n) 12 11 10 9 8 7 6 5 1 3 5 7 8 10 12 14 24 18 12 6 4 3 2 1 Writing Math Explain how you could write a function rule for problem 3 using multiplication. Reteach Use with text pages 196–198. Copyright © Houghton Mifflin Company. All rights reserved. 73744_C9L3_RET_CLN2.indd 19 7/12/07 7:52:47 PM