X-100=(Y+Z)×2／13 y-100=(x+z)×9／16 z-90=(x+y)×1／3
问题描述：
X-100=(Y+Z)×2／13 y-100=(x+z)×9／16 z-90=(x+y)×1／3
答
整理
13x-2y-2z=1300 (1)
9x-16y+9z=-1600 (2)
x+y-3z=-270 (3)
(1)+(3)×2
15x-8z=760 (4)
(2)+(3)×16
25x--39z=-5920 (5)
(4)×5-(5)×3
77z=21560
z=280
x=(39z-5920)/25=200
y=(x+z)×9/16+100=370