story problem: Reese has $225 in $10-bills and $5-bills

[era]

Please help me with this story problem:

Reese has $225 in ten dollar bills and five dollar bills. The number of five dollar bills is 15 more than the number of ten dollar bills. How many of each does he have? This is how I set it up, but I didn't get the right answer.

x= number of ten dollar bills
y=number of five dollar bills

10x(+15)+5y=225

Thanks!

 

[arthur ohlsten]

let x = number $10 bills
let y= number $5 bills

but y=x+15 15 more $5 bills than $10 bills

10x +5y=225
but y = x+15
10x+5[x+15]=225
10x+5x+75=225
15x=150
x=10
then y=25

Arthur

 

[era]

Thank you very much!

 

[arthur ohlsten]

your welcome. Now that you see the approach, be sure to do it yourself.
You learn from the errors that you make.
Arthur