pic puzzle of the day
-a + b - c + d = 0
-2a + b + c - 3d = 0
a + 2b - 3c + d = 0
2a + 3b + 4c - d = 0
a=? b=? c=? d=?
created by Niki99
-a + b - c + d = 0
-2a + b + c - 3d = 0
a + 2b - 3c + d = 0
2a + 3b + 4c - d = 0
a=? b=? c=? d=?