Lets 5 = a
square root 5 = b
then (a+b)(a-B) =
a2 - b2 =
(5)2 – (square root of 5)2 =
25-5 = 20
square root 5 = b
then (a+b)(a-B) =
a2 - b2 =
(5)2 – (square root of 5)2 =
25-5 = 20