Answer: 9) D 10) E 11) E 12) D
<u>Step-by-step explanation:</u>
Notes: The difference of squares is a² - b² = (a - b)(a + b)
To solve, take the square root of the first term and the square root of the last term. The factors are the sum and difference of those values.
9) x² - 4
a = √x² = x
b = √4 = 2
Factors: (x - 2)(x + 2)
Answer: D
10) x² - 25
a = √x² = x
b = √25 = 5
Factors: (x - 5)(x + 5)
Answer: E
11) 36x⁴ - 4x²
Factor out the common term (4x²) --> 4x²(9x² - 1)
a = √9x² = 3x
b = √1 = 1
Factors: 4x²(3x - 1)(3x + 1)
Answer: E
12) x² + 100
The plus (+) sign means this is not in the form of a² - b²
so it cannot be factored over the Real #s using this method
Answer: D
