This document provides examples and steps for teaching students how to multiply binomials using the double distributive method. It begins with examples using algebra tiles to model multiplying binomials like (x+3)(x+2). Students are then asked to conjecture a rule based on these examples. The document explains the double distributive method for multiplying binomials by distributing both terms from the first binomial to the second binomial and combining like terms. Students are given examples to practice the method.

1. AIM: Multiplying Binomials
Do Now
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2. 15x5
8x7y4
15m2 ­ 18m
­10x3 + 15x
21a4b5
12x3y ­ 9 xy2 + 6xy
­20c3 + 10c2
= ­20a5b3 + 28a2b2 ­ 4a2b
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3. Anticipatory Set
Find the following area.
(x + 3)
(x + 2)
(x + 3)(x + 2)
2 x
x 1
1.) What are the dimensions of the algebra tiles above?
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4. (x + 3)(x + 2)
REMOVED
PIECES
2 x x
x
x
x
1 1 1
x
1 1 1
2 2 x x 1 ­1
x x
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5. (x - 3)(x + 3)
REMOVED
PIECES
2
x
­1 ­1 ­1
­1 ­1 ­1
­1 ­1 ­1
x
x x x
x
x
2 2 x x 1 ­1
x x
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6. (x - 1)(x - 4)
REMOVED
PIECES
2 x
x
x
1
x
1
x
1
x
1
2 2 x x 1 ­1
x x
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7. (x + 2)(x - 3)
REMOVED
PIECES
2
x
x
­1 ­1
­1 ­1
­1
­1
x
x
x
x
2 2 x x 1 ­1
x x
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8. Conjecture: Based on the examples we have
completed, how would you multiply binomials
if you did not use the clips? (We are
creating an algebraic method)
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9. (x + 5)(x + 2)
REMOVED
PIECES
2 2 x x 1 ­1
x x
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10. (2x - 1)(x + 2)
REMOVED
PIECES
2 2 x x 1 ­1
x x
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11. (x + 2)(x - 4)
REMOVED
PIECES
2 2 x x 1 ­1
x x
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12. Rule:
Double Distributive Method: Distribute
both terms from the first binomail to the
second binomial. Simplify by combining like
terms.
(x + 3)(x - 2)
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13. Multiply the following binomials.
1.) (x - 6)(3x - 9)
2.) (2x + 4)(2x + 6)
3.) (x - 7)(x + 4)
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14. BEFORE YOU LEAVE
How close were you to the real rule when you created your personal
rule based on the work with the algebra tiles?
What steps did you not put in your rule?
Was there any parts of your rule that were unnecessary?
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15. Mr. Tjersland's Math 7
Homework: None
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