Question 172863
let n be the number of nickels and q be the number of quarters
:
.05n+.25q=7.70
.05q+.25n=4.90---->.25n+.05q=4.90
:
mulitply 1st equation by -5
:
-.25n+-1.25q=-38.5..revised eq 1
 .25n+  .05q=4.90
:
-1.2q=-33.6
:
{{{highlight(q=28)}}}quarters
:
.05n+.25(28)=7.70
:
.05n=.70
:
{{{highlight(n=14)}}}nickels
: