I think the Answer is 4d-6
But it's not one doesn't always have to be the gcf
You simply divide 78 by 3, so the answer will be 26.
The question is asking to choose among the following choices that states the temperature of the metal after five hours, and base on my research and further calculation, the possible answer among the following is 26 degree. I hope you are satisfied with my answer and feel free to ask for more if you have question and further clarifications
You just subtract 4 from 20
20-4 which is 16