algebre equation plz help!?

Question

maya hes three times as many dimes as nickels. she has four more quarters than nickels. if the value of the coins 9.40, how many nickels does maya have...when you are finished plzzzz give me the # of nickels, # of quarters, value of the dimes, and value of the quarters...if you can help it would be MMMUUUCCCHH appreciated!!!!! pllzzz help me!!!

Answer 1

so dimes + nickels + quarters = 940
d= # of dimes n = # nickels q = # quarters
d = 3n and quarters = n + 4

so 10d + 5n + 25q = 940
substitue for n
10(3n) + 5n + 25(n +4) = 940
30n + 5n + 25n + 100 = 940
60n +100 = 940
60n = 840
n = 14

d = 3n = 3 x 14 = 42
q = 14 + 4 = 18
check
18 q = 450
42 d = 420
14 n = 70

by george - I think we've got it!!!!!!!!!!

tada!

half of the problem is figuring out HOW to work the silly thing
all the best

Answer 2

Let n be the number of nickels, d be the number of dimes and q be the number of quarters.

d = 3n (three times as many dimes as nickels)

q = n + 4 (four more quarters than nickels)

5n + 10d + 25q = 940 (the total value is $9.40, or 940 pennies)

Three equations, three unknowns - you should be able to solve from here. Hint: plug the first two equations into the third. That'll give you nickels, and it's all beer and skittles from there.

Answer 3

(1) D = 3N
(2) Q = N + 4
(3) .1D + .25Q + .05N = 9.40

(1) D = 3N
(2) Q = N + 4
(3) substitute for D and Q:
0.1D + 0.25Q + 0.05N = 9.40
0.1(3N) + 0.25(N+4) + 0.05N = 9.40
0.3N + 0.25N + 1 + 0.05N = 9.40
.6N = 8.40
N = 8.40/0.6 = 14
D = 3N = 42
Q = N + 4 = 18

Value of nickels = 14 * 0.05 = $0.70
Value of dimes = 42 * 0.10 = $4.20
Value of quarters = 18 * 0.25 = $4.50

$4.50 + $4.20 + $0.70 = $9.40

Hope this helps! :)