Let the number of nickels be x
Then the number of dimes, using
ONE PART = TOTAL MINUS OTHER PART,
is 50-x.
Value Value
Type Number of of
of of EACH ALL
coin coins coin coins
-------------------------------------------
nickels x $0.05 $0.05x
dimes 50-x $0.10 $0.10(50-x)
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TOTALS 50 ----- $4.30
The equation comes from the column on the right
0.05x + 0.10(50-x) = 4.30
Get rid of decimals by multiplying every term by 100:
5x + 10(50-x) = 430
5x + 500 - 10x = 430
-5x + 500 = 430
-5x = -70
x = 14 = the number of nickels.
The number of dimes is 50-x or 50-14 or 36 dimes.
Checking: 14 nickels is $0.70 and 36 dimes is $3.60
That's 50 coins.
And indeed $0.70 + $3.60 = $4.30
Edwin
You can put this solution on YOUR website! .
N=Number of nickels; D=number of dimes
N+D=50
D=50-N Use this to substitute for D below.
.
$0.05N+$0.10D=$4.30 (This converts number of coins to value) Substitute for D.
$0.05N+$0.10(50-N)=$4.30
$0.05N+$5.00-$0.10N=$4.30 Subtract $5.00 from each side.
-$0.05N=-$0.70 Divide each side by -$0.05.
N=14 ANSWER 1: There are 14 nickels in the jar.
.
D=50-N=50-14=36 ANSWER 2: There are 36 dimes in the jar.
.
CHECK:
$0.05N+$0.10D=$4.30
$0.05(14)+$0.10(36)=$4.30
$0.70+$3.60=$4.30
$4.30=$4.30
You can put this solution on YOUR website! A jar contains 50 nickels and dimes worth $4.30. How many of each kind of coin are in the jar?
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A different method:
50 nickels = $2.50
Each dime adds 5 cents to the total
---
430 - 250 = 180
180/5 = 36 dimes
14 nickels