quadratic Equations

Question

xy x+y if x=5+2 square root of 6 , y=5−2 squareroot of 6

xy

x+y

 if x=5+2

6

, y=5−2

6

Answer 1

x = 5 + 2sqrt(6)

y = 5 - 2sqrt(6)

 

x + y = 5 + 2sqrt(6) +5 - 2sqrt(6) = 10     as 2sqrt(6) gets cancelled out

To calculate x*Y, you need to use the following formula:  (a+b)*(a-b) = a^2 - b^2

x*y = 5^2 - (2*sqrt(6))^2

= 25 - 4*6 = 25 - 24 = 1