Equations:
q + d = 14
0.25q + 0.10d = 2.60
-0.10( q + d = 14 )
0.25q + 0.10d = 2.60
-0.10q - 0.10d = -1.4
0.25q + 0.10d = 2.60
Add up the two equations
0.15q = 1.20
/0.15 on both sides
q = 8
q + d = 14
8 + d = 14
-8 on both sides
d = 6
0.25q + 0.10d = 2.60
0.25(8) + 0.10(6) = 2.60
2 + 0.60 = 2.60$
Answer:
8 Quarters
6 Dimes