You have $3.20 in quarters and dimes. You gave four fewer quarters than dimes.

What is the equation for this? They also want me to then answer in augmented matrix form, but I can do that easily, I just need the equation since I just get really mixed up trying to figure it out:/ Please help? Thanks

3 answers

*have... not gave
number of dimes ---- x
number of quarters --- x-4

equation based on value:
10x + 25(x-4) = 320

etc
Ok, great, thanks again Reiny!