<PRE><B>Question 558082</B>
let x = original number dimes
Let y = original number of quarters
:
man has twenty coins consisting of dimes and quarters.
x + y = 20
:
if the dimes were quarters and the quarters were dimes, he would have ninety cents more than he has now.
(10y + 25x) - (10x + 25y) = 90
10y + 25x - 10x - 25y = 90
25x - 10x + 10y - 25y = 90
15x - 15y = 90
simplify, divide by 15
x - y = 6
x + y = 20; added the 1st equation
------------eliminates y find
2x = 26
x = 13 dimes originally
then
20 - 13 = 7 quarters
;
:
See if that checks our
13(25) + 7(10) = 395
13(10) + 7(25) = 305
----------------------
difference is 90






..how many dimes and quarters does he have now? 13, 7</PRE>