Answer:
This is a system of equations, meaning there are two equations you will need to use. The first equation would be d + n = 35, where d = dimes and n = nickels. The second equation would be 10d + 5n = 250, since each dime is 10 cents and each nickel is 5 cents totaling at 250 cents. To solve for nickels, solve one equation for dimes and substitute the answer into the d in the other equation. If you need any more help with this one I am happy to help.
Explanation: