Solution:Concept: Write 49 as 50 - 1 to evaluate using the identity = then compare and replace the values in the supplied identity.
We can write as
Take a = 50 and b = 1, and replace them in the expansion of the formula for calculating the value in mathematical form.
The value of is 2500
2500 + 1−100
So, the value of using the identity = is 2401.
Hence, option 1 is correct.