Find all pairs (x,y) of real numbers such that x + y = 10 and x^2 - y^2 = 56.
(7.8, 2.2)
to solve y = 10 - x
then x^2 - y^2 = 56
x^2 - (10-x)^2 = 56 <===== solve for 'x' then 'y' = 10 - x
+36915 
