Question

Using a^2-b^2=(a+b)(a-b),find
51^2-49^2

Answer 1

Answer:

$we \: have \: \\ = {a}^{2} - {b}^{2} = (a + b)(a - b) \\ = {51}^{2} - {49}^{2} = (51 + 49)(51 - 49) \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: = (100)(2) \\ \\ \\ hence \: the \: answer \: is \: 200$