They are SQUARE NUMBERS.
For English speaking people, the numbers are in alphabetical order.
The numbers are in alphabetical order of their names in the English language.
499 + 49
Two numbers with a sum of 4 and a difference of 9 are -6.5 and 2.5.
They are SQUARE NUMBERS.
They are all perfect square numbers.
The numbers are 4 and 5: 4 + 5 = 9
They are 'square' numbers. 6x6=36, 9x9=81 and 5x5=25. Some other square numbers are 64, 4, 9, 100 & 121
For English speaking people, the numbers are in alphabetical order.
Sure. But since negative numbers have positive factors and positive numbers are greater than negative numbers, the answer will be the same regardless of the sign. The GCF of 4 and 9, -4 and 9, 4 and -9 and -4 and -9 is 1.
The numbers are in alphabetical order of their names in the English language.
13
499 + 49
It is any sequence of numbers. For example: 1 3 5 7 9 11 .... - this is the sequence of odd numbers. 1 4 65 4556 4 3 76 ... - this is probably not a special sequence at all.
Two numbers with a sum of 4 and a difference of 9 are -6.5 and 2.5.
36/9 = 4 36 - 9 = 27 The two numbers are therefore 9 and 36.