Answer:
n = 20d
Explanation:
To write an equation, define variables. n will be the number of nickels. d will be the number of dollars. We want to know the number of nickels so the equation will be equal to n. Since there are 20 nickels in each dollar, 1 dollar will have 20 nickels. 2 dollars will have 40 nickels or 2*20. For d dollars, it will be 20d.
n = 20d