Respuesta :

A) D + N = 32

B) .1D + .05N = 2.80 multiplying A) by -.1

A) -.1D -.1N = -3.2  then adding this to B)

-.05N = -.4

Nickels = 8   Dimes = 24

*************** DOUBLE-CHECK

.1 * 24 + .05 * 8 = 2.80 ||| 2.40 + 40 = 2.80