Question 97820
q+d=66
.25q+.10d=13.80
multiply the bottom equation by 4 and subtract the top from the bottom.
q+.4d=55.2
q+d=66
-----------
-.6d=-10.8
divide -.6 into each side. d=18
replace d with 18 in the 1st equation. q+18=66
q=66-18
q=48
replace q & d with 48 & 18 respectively in the second equation.
.25*48+.1*18=13.8
12+1.8=13.8
Ans.= $12.00 in quarters. $1.80 in dimes.
Ed