contestada

Kevin has a jar containing 63 coins, all of which are either quarters or nickels. the total value of the coins is $12.55. how much of each type of coins do they have

Respuesta :

x+y=63
.05x+.25y=12.55

x=63-y

.05(63-y)+.25y=12.55
3.15-.05y+.25y=12.55
.20y+3.15=12.55
.20y=9.4
y=47

47 quarters and 16 nickels