youngpa35
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Joanna has a total of 7 rolls of coins worth $23. She has rolls of dimes worth $5 each, and
rolls of nickels worth $2 each.
How many rolls of each kind does she have?
4 rolls of dimes and 3 rolls of nickels
2 rolls of dimes and 5 rolls of nickels
5 rolls of dimes and 2 rolls of nickels
3 rolls of dimes and 4 rolls of nickels​

Joanna has a total of 7 rolls of coins worth 23 She has rolls of dimes worth 5 each androlls of nickels worth 2 eachHow many rolls of each kind does she have4 r class=

Respuesta :

devishri1977

Answer:

3 rolls of dimes and 4 rolls of nickels

Step-by-step explanation:

Number of rolls of dimes = x

Number of rolls of nickels = y

Total number of rolls = 7

x + y = 7        -------------------(i)

Total amount = $ 23

5x + 2y = 23 ----------------(ii)

Multiply equation (i) by -2. So when we are adding, y will be eliminated and you will get the number of rolls of dimes.

(i)*(-2)              -2x - 2y = -14

(ii)                    5x   + 2y = 23    {Now add}

                       3x            = 9

x = 9/3

x = 3

Plug in the value of x in equation (i)

3 +y = 7

y = 7- 3

y = 4

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