( )—( )=9

+ +

( )—( )= 14

|| ||

12 2

Suppose: X-Y = 9, Z-W = 14, X+Z = 12, Y+W = 2.

Then:

x-y=9( 1)

x+z= 12(2)

z-w= 14(3)

y+w=2(4)

(4)+(3):z-w+y+w=2+ 14

y+z= 16(5)

(2)-( 1):x+z-x+y = 12-9

y+z=3(6)

(5)(6) Contradictions

Therefore, the original equations have no solution.

It is this problem that has no solution.