(7,4x - 12,3x) - (1,56 - 2,3x ) = 2,6x
7,4х-12,3х-1,56+2,3х=2,6х
-2,6х-1,56=2,6х
-2,6х-2,6х=1,56
-5,2х=1,56
х=1,56: (-5,2)
х=0,3