I'm using examples to show
9
a) Let,
First odd number = 5
Second consecutive odd number = 7
Sum = 5 + 7 = 12. Which is divisible by 4
b) Let the numbers be same as above
(5)² + (7)²
25 + 49
74. Which is not divisible by 4
10) Maisy is wrong because 2 has no common factor except 1 and 2. And we know that 2 is an even number and it is also a prime number
11)
a) Let,
First integer = 5
Second integer = 7
Sum = 5 + 7 = 12.
Since the sum is even but the integers are odd.
b) Let,
Integer = 8
(8)² = 64. which is divisible by 4 and 8 is also divisible by 4
12)
Let,
a = -8
b = 8
a² = (-8)² = 64
b² = (8)² = 64
a² = b²
But, a ≠ b