Respuesta :
There is 4 roll of coins of nickel and 3 rolls of coins of dimes.
Given that,
Joanna has a total of 7 rolls of coins worth $23.
She has rolls of dimes worth $5 each and rolls of nickel worth $2.
We have to determine,
How many rolls of each kind does she have?
According to the question,
Let the number of coins of dimes be x
And the number of coins of nickel be y.
Then,
The number of coins of dimes + Number of coins of nickel = Total number of coins.
[tex]\rm x+ y =7[/tex]
And the total price of the coins is equal to the price of each coin of dimes and nickel.
[tex]\rm 5x+2y=23[/tex]
Solving both the equation,
From equation 1,
[tex]\rm x+ y = 7\\\\x = 7-y[/tex]
Substitute the value of x in equation 2,
[tex]\rm 5x+2y = 23\\\\5(7-y) +2y = 23\\\\35-5y+2y=23\\\\-3y = 23-35\\\\-3y = -12\\\\y = \dfrac{-12}{-3}\\\\y = 4[/tex]
Substitute the value of y in equation 1,
[tex]\rm x+y = 7\\\\x+4 = 7\\\\x = 7-4\\\\x =3[/tex]
Hence, there is 4 roll of coins of nickel and 3 rolls of coins of dimes.
To know more about System of Equation click the link given below.
https://brainly.com/question/12895249
