Question 44962
(1- sqrt of 5)(1 + sqrt of 5)
(1)(1)+ (1)(sqrt5)-(sqret5)(1)-(sqrt5)(sqrt5) [Use the FOIL method to multiply]
1 - (sqrt5) + (sqrt5) - (sqrt5)^2  [Multiply and simplify]
1  - (sqrt5)^2 [The middle terms cancel out; (sqrt5)^2 = 5]
1 - 5  [Simplify]
-4 [Answer]