Answer:
.25q+.10d=25.10
q+d=128
Step-by-step explanation:
Since a quarter is 25 cents and a dime is 10 cents that is how you figure out your first equation. You set it equal to 25.10 because that is the amount of money it totals to. The second equation (q+d=128) is used because the amount of quarters plus dimes needs to make 128.