N + 2d =1
This is the system of equations because it is 2 times more than nickels
Answer:

Step-by-step explanation:

1/3 (0.333,,,) is 0.05666... away from 0.39 .
2/5 (0.4) is 0.01 away .
3.8 (0.375) is 0.015 away .
9/25 (0.36) is 0.3 away .
2/5 is the closest one.
It is really easy it is 6
1. 1/9
2. 0
3. -9
4. -1
Reasoning: To get the opposite of a number just add a negative sign or take it away. This can be done to all numbers other than 0