The temp. started at -20. If it rose +8 degrees, then it would be -20+8=-12, because since the -20 and +8 are opposites, you would subtract them and the answer would have the sign of the larger number which is -. so -12 is the answer.
Step-by-step explanation:
since the -20 and +8 are opposites, you have to subtract them and you get -12
