1 to 4
Step-by-step explanation:
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
Answer:
Option 'b' i.e. -11/20 is the correct option.
Thus,

Step-by-step explanation:
Given the expression

Determining the difference of the fractions

The Least Common Multiplier of 5, 4 is 20. Thus, adjust the fractions based on the L.C.M.

Apply the fraction rule: 

Add the number: 4-15 = -11

Apply the fraction rule: 

Please check the attached figure, where the pointing-down arrow is representing the correct answer which is -11/20.
Therefore, option 'b' i.e. -11/20 is the correct option.
Thus,

You need 1 cup of sugar, 9/4 cups of flour and 3/2 cups of milk