6d-11/2=2d-13/2
6d - 11/2 = 2d - 13/2 ADD 11/2 to both sides of the equation
6d - 11/2 +11/2 = 2d - 13/2 + 11/2
6d = 2d - 2/2 SUBTRACT 2d from both sides
6d -2d = 2d - 2d - 2/2
4d = -2/2
4d = -1 DIVIDE both sides by 4
d = -1/4 = -.25