Answer:#of dimes is 15 # of quarters is 10
Step-by-step explanation:method is elimination my multiplication. First equation is x+y=25 multiply it by -10. Second equation is 10x+25y=400. A quarter is .25 and a dime is .10 but to avoid all decimals I multiplied by 10 but it doesn’t matter because I did it on both sides. Use systematic equation solving to get 15y=150 then y=10. Plug it into the first to get x+10=25 subtract to get 15. Mr. Jacobs does get excessive sometimes lol.