SOLUTION: A jar full of nickels and dimes contains 180 coins . If the total amount of money contained in the jar is $13.000, how many nickels are in the jar? I set up the equation, $0.0

Algebra ->  Expressions-with-variables -> SOLUTION: A jar full of nickels and dimes contains 180 coins . If the total amount of money contained in the jar is $13.000, how many nickels are in the jar? I set up the equation, $0.0      Log On


   

Question 44768: A jar full of nickels and dimes contains 180 coins . If the total amount of money contained in the jar is $13.000, how many nickels are in the jar?
I set up the equation,
$0.05x + 0.10y = $13.00
and x + y = 180
x=nickels and y=dimes
i really don't remember how to solve it now, since it has two variables...please if someone could help me, i would really appreciate it [please by today?] thanks
Found 2 solutions by OHtutor, adamchapman:
Answer by OHtutor(16) About Me  (Show Source):
You can put this solution on YOUR website!
Your equations are set up correctly.
x+y=180
.05x+.10y=13
I rewrite the 2nd quation like this (multiplying by 100)
5x+10Y=1300
-----------
x=180-y
5(180-y) +10y=1300
930-5y+10y=1300
5y=1300-930
5y=370 y=370/5=54
x=180-54=126
x=126(nickels)
y=54(dimes)

Answer by adamchapman(301) About Me  (Show Source):
You can put this solution on YOUR website!
Just get your equation x%2By=180, rearrang to give y in terms of x:
y=180-x
Now substituite this into the other equation you started with:
%240.05x%2B%240.1y=%2413
%240.05x%2B%240.1%28180-x%29=%2413
0.05x%2B18-0.1x=13
-0.05x%2B18=13
0.05x=5
0.01x=1
x=1%2F0.01
x=100
Now substitute this value of x into your equation for y:
y=180-x
y=180-100=80
So the pot contains 100 nickels and 80 dimes.
I hope this helps.
P.S. I am trying to start up my own homework help website. I would be extremely grateful if you would e-mail me some feedback on the help you received to adam.chapman@student.manchester.ac.uk
Adam