Is there a picture? I can’t see one
Answer: all real numbers
Step-by-step explanation:
7a + 1 = 8a - a + 1
7a + 1 = 7a + 1
a = all real numbers
Good luck.............................
I would say C.
A and B make no sense, you want to divide the group randomly because you want to test the new medicine. D is a bit more logical than A and B but still can't, because that isn't random.