The water level in a tank is lowered by 6 inches, then raised by 8 inches, and then lowered by 4 inches.If the water level was x inches before the changes in level, which of the following represents the water level, in ches, after the changes(a)
a x-1.5
b x+1.5
c x-6.5
d x+6.5
e x-18.5
我完全不明白怎么会有0.5出现的,我的理解是x-6+8-4=x-2