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Prove that the sum of the squares of two odd numbers leaves remainder 2 on division by 4?

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Final Answer:

Yes, the sum of the squares of two odd numbers always leaves a remainder of 2 when divided by 4.

Step-by-step explanation:

Let's consider two odd numbers, a and b. We can express them as follows:

a = 2m + 1

b = 2n + 1

where m and n are integers.

Now, let's calculate the sum of their squares:

a² + b² = (2m + 1)² + (2n + 1)²

Expanding the squares, we get:

a² + b² = 4m² + 4m + 1 + 4n² + 4n + 1

Combining like terms, we get:

a² + b² = 4(m² + n²) + 4(m + n) + 2

Since m² and n² are integers, 4(m² + n²) is also an integer. Similarly, 4(m + n) is also an integer. Therefore, the sum of the squares of two odd numbers can be expressed as:

a² + b² = 4k + 2

where k is an integer.

This means that the sum of the squares of two odd numbers is always of the form 4k + 2, which when divided by 4 leaves a remainder of 2.

User Maksim Nikolaev
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