46.3k views
0 votes
Andres has $1.50 in dimes and nickels. If he has 9 more nickels than dimes, how many of each coin does he have?He has ? nickels and ? dimes.

User Jahooma
by
4.7k points

1 Answer

7 votes

Let's use the variable x to represent the number of dimes and y to represent the number of nickels.

If the total value is $1.50, we can write the equation:


0.1x+0.05y=1.5

Also, if there are 9 more nickels than dimes, we have our second equation:


y=x+9

Using this value of y from the second equation into the first one, we have:


\begin{gathered} 0.1x+0.05(x+9)=1.5 \\ 0.1x+0.05x+0.45=1.5 \\ 0.15x=1.5-0.45 \\ 0.15x=1.05 \\ x=(1.05)/(0.15) \\ x=7 \\ \\ y=x+9 \\ y=7+9 \\ y=16 \end{gathered}

Therefore Andres ha 16 nickels and 7 dimes.

User Gustavo Bezerra
by
4.8k points