Remark
What this is trying to tell you is that you have two factors. Each in turn can be zero, but they cannot be zero at the same time. You will get that kind of question, just not now.
So either - n = 0 or 5n - 4 =0
Solution
- n = 0 Multiply both sides by - 1
(-1)*(-n) = 0*-1
n = 0
5n - 4 = 0 Add 4 to both sides.
5n = 4 Divide by 5
n = 4/5
Comment
B and D are both wrong 4/5 is positive. and those list n as -4/5 which is wrong.
A is wrong because the function will not go to 0 if n = -1
Answer
C <<<<Answer