Respuesta :
Answer:
There are 9 dimes in this collection.
Step-by-step explanation:
Dimes are 10¢; nickels are 5¢.
d + n = 31
0.1d + 0.05n = 2
In this system of equations, d represents the amount of dimes in this collection and n represents the amount of nickels in this collection.
1. Isolate n in the first equation.
n = -d + 31
2. Substitute this value into the other equation to find the value of d.
0.1d + 0.05(-d + 31) = 2
0.1d - 0.05d + 1.55 = 2
0.05d + 1.55 = 2
0.05d = 0.45
d = 9
If you'd like to know how many nickels are in the collection, just subtract the amount of dimes from the total number of coins in the collection.
31 - 9 = 22
