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Simplifying Variable Expressions (Negative Units - Day 2). We are learning to…simplify variable expressions by combining like terms. Friday, October 31, 2014. Negative Units. As you are working today you may notice negative units. These units may be shown in one of two ways.
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Simplifying Variable Expressions (Negative Units - Day 2) We are learning to…simplify variable expressions by combining like terms. Friday, October 31, 2014
Negative Units • As you are working today you may notice negative units. • These units may be shown in one of two ways. • Adding negative units. • Subtracting positive units. • This is because adding a negative is the same as subtracting a positive. • So today pay attention to both the sign and the operation involved in the expression.
Negative Units • When representing Negative Units with Algebra Tiles you will use the red side of the tile. • When drawing your representations today let: • Colored in tiles represent positive units. • Open tiles represent negative units. xy xy This represents… Positive xy (+xy) This represents… Negative xy (-xy)
With your team: • Draw 2 different representations of 0 with Algebra Tiles. • Write the expressions that represent the tiles. Negative Units • Remember…when a positive unit and a negative unit are put together we create a… ZERO PAIR For example the expression below would represent zero: x2 x2 + This expression could be written two different ways: x2 + (-x2) = 0 x2 – x2= 0 OR
Simplify the expression below: -2x + 3y – 3x + (-x2) – y + 4x2 Make Zero Pairs: Represent the expression with Algebra Tiles: Organize the Algebra Tiles so that similar units are next to one another: x y x2 x x2 x y y y x x x2 x2 x2 Write the simplified version of the expression: 2y – 5x + 3x2
Simplify the expression below: xy + 4 – 2y2 – 2xy + (-4) – 2y2 Make Zero Pairs: Represent the expression with Algebra Tiles: Organize the Algebra Tiles so that similar units are next to one another: y2 y2 xy 1 1 xy y2 y2 1 1 xy 1 1 1 1 Write the simplified version of the expression: -xy – 4y2
Practice… • Now try some practice with your team. • Directions: • Read each expression carefully. • Use your Algebra Tiles to create a representation of the expression. • Draw your representation with Algebra Tiles. • Organize your tiles so that you combine like terms in the expression. • Create Zero Pairs. • Write your simplified expression.