On a temperature versus time graph, how does the temperature at the beginning of a change of state compare with the temperature at the end of the change? always lower always the same usually lower usually higher

Always the same

Step-by-step explanation:

The temperature at the beginning of a change of state is always the same as the temperature at the end.

This is because phase change is an isothermal process. it means that all the energy absorbed during the phase change process is utilized in the breaking of the bonds in the compound as it changes from one state of matter to another.

As a result, no increase in the temperature of the material will be detected by the thermometer.

12r - 8 - 12

you have to combine like terms. below i have bolded the like terms:

12r - 8 - 12

together it combines to:

12r - 20

hope this !