2x² - 128
2(x² - 64), but (x² - 64) = x² - 8² (difference of 2 squares),[a²-b²=(a-b)(a+b)]
2(x² - 64) = 2(x² - 8²) = 2(x-8)(x+8)
a. Use the inclusion/exclusion principle.

b. By definition of conditional probability,

Answer:
1
Step-by-step explanation:
7 + 2x = 9
Carry over the 7 to the 9.
2x = 9-7
2x= 2
x = 2÷2
x = 1
A² + b² = c²
a² = c² - b²
a² = 9² - 6²
a² = 81 - 36
a² = 45
a = √45
a ≈ 6.7082
a = 6.7