Question 110884
"----There were 3 times as many quarters as nickels----" I BELIEVE THIS WOULD BE WRITTEN AS: Q=3N
Let Q=number of quarters
D=number of dimes
N=number of nickels
N+D+Q=135----------------------------eq1
5N+10D+25Q=2350--------------------------eq2
Q=3N--------------------------------------eq3

Multiply eq1 by 10 and subtract it from eq2 and we get
   5N+10D+25Q=2350
(-)10N+10D+10Q=1350

-5N+15Q=1000  Now substitute Q=3N from eq3 into this

-5N+15(3N)=1000
-5N+45N=1000
40N=1000
N=25----------------------------number of nickels
Q=3N
Q=3*25=75------------------------number of quarters

From eq1:

N+D+Q=135

25+D+75=135
D=35------------------------------------number of dimes

CK

10*35+75*25+25*5=2350
350+1875+125=2350
2350=2350



Hope this helps---ptaylor