Simple....
you have:

You're trying to find b..so isolate it...

leaving you
a=c*b
still not done....


Thus, your answer.
Answer:
B
Step-by-step explanation:
Only 1 because
1/1 = 1
2/1 = 2
The answer can't be 0 because we can't divide by zero.
The answer can't be 2 because you can't divide 1 by 2 without having a number with decimal places
Same thing for the 4
Answer:
B
Step-by-step explanation:
Not much to explain
Answer:
a and c
Step-by-step explanation: