Japanese | Can you solve this? | Math Olympiad

[@wes9627]

x=5+z, y=5-z; (5+z)(5-z)=10; z^2=15; z=±√15; x=5±√15 and y=5∓√15

[@johnmaulkin-ur8lm]

Well done.

[@cyruschang1904]

x + y = 10 => y = 10 - x
xy = x(10 - x) = 10x - x^2 = 10
x^2 - 10x + 10 = 0
x = 5 +/- ✓15
(x, y) = (5 + ✓15, 5 - ✓15), (5 - ✓15, 5 + ✓15)