Question

Easy question, i just suck at math. HELP PLEASE!

Sam has 15 coins, all nickels and dimes, with a total value of $0.90. How many of each coin does he have? (Let d = the number of dimes and n = the number of nickels).

A. Write a system of equations to model the problem.

B. Solve the system.

C. State your answer with the proper label or labels.

Answer 1

It is a system of equations

15 coins in all...all nickels and dimes,,,let d = dimes and n = nickels

d + n = 15

The total amount of money = .90 cents so

.10d + .05n = .90




our 2 equations

d + n = 15
.10d + .05n = .90

can you solve it from here?

Answer 2

Can you please actually solve it for me? I really am horrible at math, and I can't do this one at all.

Answer 3

d + n = 15 --> d = 15 - n
.10d + .05n = .90
sub 15 - n in for d in the 2nd equation
.10d + .05n = .90
.10(15 - n) + .05n = .90 (distribute through the parenthesis)
1.50 - .10n + .05n = .90 (combine like terms)
1.50 - .05n = .90
-.05n = .90 - 1.50
-.05n = - .60
n = - .60/-.05
n = 12
now sub 12 into the first equation
n + d = 15
12 + d = 15
d = 15 - 12
d = 3
check...
.05n + .10d = .90
.05(12) + .10(3) = .90
.60 + .30 = .90
.90 = .90 (correct)
There is 3 dimes and 12 nickels

Answer 4

Excellent work @texaschic101 :)

Answer 5

thank you....I probably should not have given the answer....I was just giving @PuppyPawsB a little break :)

Answer 6

thanks so much @texaschick101