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Activity 2 Evaluating Algebraic Expressions

Thomas is twelve years old. He has a younger sister and an older brother.
Let a the age of the older brother. Let b the age of the younger sister.

If the ages of Thomas and his older brother add up to 29, how old is Thomas’
older brother?

Let a the age of the older brother.
12 a 29

years old

What is the age difference between Thomas and his younger sister if his
younger sister is nine years old?

Let b the age of the younger sister.
12 12

years

1 . Evaluate each expression for the given value of the variable.

a. x 5 if x 3 b. x 3 if x 6

Replace x with 3 and add.
x5358

c. y 7 if y 10 d. y 10 if y 4

e. a 4 if a 5 f. b 5 if b 7

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