Well what is it equal to? If it is equal to zero you would solve like this. 4c - 3c = 0 First you combine like terms (the c in this case) 4c - 3c = 1c or just c Therefore c = 0

No, pressure affects the freezing point of substances. When you increase the presure, you lower the freezing point. So if you kept water at -4C then increased the pressure enough, the water would start to freeze

The volume of a cube is width times depth times height and all sides are equal because it is a cube, therefore the volume is (4C) cubed or 64 (C)cubed.