1. Answers to Homework
8) (x + 6)(2x + 1) 10) (2n – 3)(2n – 1) 12) (2r – 5)(3r – 4) 14) (5z – 1)(z + 4) 16) (2t – 1)(3t + 5) 18) (4w + 3)(w – 2) 20) (2x + 7)(4x + 1) 22) 4(3p – 1)(p + 2) 24) 3(s + 8)(2s + 3) 26) 2(6x + 1)(x – 4)

2. 8-7 Factoring Special Cases
Remember:
(a + b)(a – b) = a2 – b2
(2x – 8)(2x + 8) =
4x2 – 64
(2x)2 –
(8)2

3. Difference of Squares a2 – b2 Can take square root of both numbers
Minus sign in the middle
49 – y2

4. TOO: Is it a Difference of Squares?
x2 – 4
9x2 – 1
2x2 – 4
2x2 – 8
x2 + y2
x3 – 25
9xy – y2
-16 + x2
-4 – 16x2
x4 – 81
YES
NO √2
YES 2(x2 – 4)
NO Adding
NO x3
NO x
YES x2 – 16
NO (1 + 4x2)
YES √x4 = x2
Do your WoW for today

5. Difference of Squares a2 – b2 Answer: (a + b)(a – b)
Take square root of each number
Write one parenthesis with a + and one with a –
49 – y2
(7 + y)(7 – y)

6. FACTOR x2 – 4 9x2 – 1 2x2 – 8 -16 + x2 x4 – 81 (x + 2)(x – 2)

7. Square Roots to Know

8. Factor using 1) GCF 2) Grouping/Box 3) X – BOX 4) Difference of Squares 5) Perfect Square Trinomial
Question
#’s
Answer
16x2 – 40x – 24
81x4 – 16y4
y2 – 6y – 16
24x2 – 8
2x3 – 3x2 + 5x
n2 + 2n + 3mn + 6m
t3 – t2 + t – 1
4a3 + 8a2 + 4a
5x2 – 45y2
1 – 8u + 16u2
1&3
4&4 3 1 2
1&5
1&4 5
8(2x + 1)(x – 3)
(9x2 + 4y2)(3x + 2y)(3x – 2y)
(y – 8)(y + 2)
8(3x2 – 1)
x(2x2 – 3x + 5)
(n + 3m)(n + 2)
(t – 1)(t2 + 1)
4a(a + 1)2
5(x + 3y)(x – 3y)
(1 – 4u)2

9. Homework Page 526 #9-37 odd, 40 Perfect Square Trinomial
Difference of Squares