х/4 + у/8 = 2
2х/9 + у/6 = 1
________________
x/4 = 2 - y/8
2х/9 + у/6 = 1
________________
x = 8 - y/2
(16 - y)/9 + y/6 = 1
________________
x = 8 - y/2
(32 - 2y + 3y)/18 = 1
________________
x = 8 - y/2
y + 32 = 18
________________
x = 8 + 14/2
y = -14
________________
x = 15
y = -14
Ответ: (15; -14)