For this case, the first thing we must do is define variables.
We have then:
x: number of nickles
y: number of quarters
We now write the system of equations.
We have then:
[tex] 0.05x + 0.25y = 3.90
y = x + 6
[/tex]
Solving the system of equations graphically we have:
[tex] x = 8
y = 14
[/tex]
Answer:
8 nickels and 14 quarters
Note: see attached image for the graphic solution.
Answer: There are 8 nickels and 14 quarters.
Explanation:
Since we have given that
there are $3.90 worth of nickles and quarters in a piggy bank.
Let the number of nickles be x
Let the number of quarters be x+6
As we know that
[tex]1\ nickle=0.05\ dollars\\\\and\\\\\ 1\ quarter=0.25\ dollars[/tex]
According to question,
[tex]0.05x+0.25(x+6)=3.90\\\\0.05x+0.25x+1.5=3.90\\\\0.3x=3.90-1.5\\\\0.3x=2.4\\\\x=\frac{2.4}{0.3}=8\\\\and \\\\x+6=8+6=14[/tex]
Hence, there are 8 nickels and 14 quarters.
