Download LHefez_L1_ Template for Practice Set C

Generate equivalent expressions by using the properties of operations
Practice Set C
Name:
Date:
1. Write three equivalent expressions for the each of the expressions below.
Be sure to include at least one with rational and negative numbers.
Explain or show how you know they are equivalent.
a. 6x - 4 - 9x +16
b. 2x + 9y -5 + 3y -10x -3
2. If we multiply + by 4, we get 2x+3.
Is 2x+3 an equivalent expression to
+
? Explain.
Generate equivalent expressions by using the properties of operations
Practice Set C Answer Key
1. Write three equivalent expressions for the each of the expressions below.
Be sure to include at least one with rational and negative numbers.
Explain or show how you know they are equivalent.
a. 6x - 4 - 9x +16
Answers will vary: -3x +12,
5x - 8x + 10 + 2, or ⅓ (-9x + 36)
or other valid expression
The expressions are equivalent because they all simplify to -3x + 12. When substituting a value
for x, each expression will evaluate to the same number.
b. 2x + 9y -5 + 3y -10x -3
Answers will vary: -8x +12y -8, 8(-x + ⅔ y -1) or 16( -½ x + 24y - ½)
or other valid expression.
The expressions are equivalent because they all simplify to -8x +12y -8. When substituting a
value for x and y each expression will evaluate to the same number.
2. If we multiply + by 4, we get 2x+3.
Is 2x+3 an equivalent expression to
+ ? Explain.
No, the expressions are not equivalent. The expression 2x + 3 is four times bigger than
the value of
+ . Therefore, when substituting a value for x, x=2, 2x + 3 = 7 and
= 1.75. 7 is 4 times 1.75. Only if the expression were multiplied by or 1, then the
expressions would have been equivalent. (identity property of multiplication)
+