Question

Your piggy bank has a total of 47 coins in it; some are dimes and some are nickels. If you have a total of $3.95, how many nickels do you have?
@JakeV8

Answer 1

dimes are 10 cents each and nickels are 5 cents each right?

Answer 2

the first two equations would be
n+d=47
&
.05n+.10d=3.95 but idk how to get the rest

Answer 3

solve them by elimination or substitution

Answer 4

substitution : n = 47 - d , then substitute this n into the other equation.
elimination :
.05 n + .1 d = 3.95 times 20 = n + 2d = 79.0
n + 2d = 79
n + d = 47

minus them :x

Answer 5

i dnt understand...

Answer 6

n + d = 47
--> n = 47 - d

then put n above into 0.05n + 0.1d = 3.95

Answer 7

.05(47-d)+0.1d=3.95
2.35-.05d+0.1d=3.95
2.35+.05d=3.95
-2.35 -2.35
.05d=1.6
/.05 /.05
d=32
???? did i do it correctly?

then it would be 47-32=15
n=15
??

Answer 8

@nphuongsun93

Answer 9

yup that's right

Answer 10

thx!