Question

(Hint: (n + 1) - n = (n + 1) + n = 2n +
5. Indicate whether the square of the following numbers are even or odd.
a. 57
b. 126
C. 289
d. 2450
e. 3001
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Answer 1

Square of any odd number can be written in the form of 4n+1.

For 3, 3

2

=9. But we can't write 9 in the form of 6n+1 where n is integer. We can write it as 4×2+1 which is in the form of 4n+1.

For 5, 5

2

=25.But we can't write 25 in the form of 6n+3 where n is integer. We can write it as 4×6+1 which is in the form of 4n+1.

21

2

=441 and we can't write it in the form of 8n+1. But we can write it as 4×110+1 which is in the form of 4n+1.

Hence, square of any odd integer must be of the form 4n+1.

Hence, option D is correct.

Answer 2

Answer:

square of 57= 3249, it is odd