I have got three more dimes than quarters. The total value of my change is $2.75. How many of each coin have I got?

2 answers

q+ 3 = d
.25q + .10d = 2.75

.25q + .10(q + 3) = 2.75

The above is a substitution.
If you don't like working with decimals, multiply through by 100

25q + 10(q+3) =275
35q + 10q + 30 = 275

Can you finish from here?
Ok ty