Let the number of nickels be x
Then the number of dimes, using
ONE PART = TOTAL MINUS OTHER PART,
is 53-x.
Value Value
Type Number of of
of of EACH ALL
coin coins coin coins
-------------------------------------------
nickels x $0.05 $0.05x
dimes 53-x $0.10 $0.10(53-x)
-------------------------------------------
TOTALS 53 ----- $3.65
The equation comes from the column on the right
0.05x + 0.10(53-x) = 3.65
Get rid of decimals by multiplying every term by 100:
5x + 10(53-x) = 365
5x + 530 - 10x = 365
-5x + 530 = 365
-5x = -165
x = 33 = the number of nickels.
The number of dimes is 53-x or 53-33 or 20 dimes.
Checking: 33 nickels is $1.65 and 20 dimes is $2.00
That's 53 coins.
And indeed $1.65 + $2.00 = $3.65
Edwin