Aaron has $0.70 worth of nickels and dimes. He has a total of 8 nickels and dimes altogether. By following the steps below, determine the number of nickels, x, x, and the number of dimes, y, y, that Aaron has.

  There are 2 nickels and 6 dimes.

Step-by-step explanation:

Nickels:  x

 Dimes:  y

Constraints:

  0.05x + 0.10y = 0.70

   x + y = 8                   ===>  -0.05 * (x + y = 8)  ===>   -0.05x - 0.05y = -0.4

Add the two equations to eliminate x variable:

  0.05x + 0.10y = 0.70

 -0.05x - 0.05y = -0.4

                0.05y = 0.3         ===>    y = 6

Substitution to find x:

  x + y = 8

  x + 6 = 8

  x = 2

There are 2 nickels and 6 dimes.

the answer is a

step-by-step explanation: