Respuesta :
Answer:
There are [tex]5[/tex] five dollar bills and [tex]4[/tex] ten dollar bills.
Step-by-step explanation:
Given:
Selling price of bicycle [tex]=\$65[/tex].
The friend gave [tex]x[/tex] five dollar bills and [tex]y[/tex] ten dollar bills.
Total number of bills [tex]=9[/tex].
To find: Number of five dollar bills and ten dollar bills the friend gave.
Solution:
The friend gave [tex]x[/tex] five dollar bills and [tex]y[/tex] ten dollar bills and the friend gave [tex]9[/tex]bills in all.
So, [tex]x+y=9[/tex].
[tex]\Rightarrow x=9-y ...(i)[/tex]
Selling price of bicycle [tex]=\$65[/tex].
So, [tex]5x+10y=65...(ii)[/tex]
Putting the value of [tex]x[/tex] from equation [tex](i)[/tex] in equation [tex](ii)[/tex].
[tex]\Rightarrow 5(9-y)+10y=65[/tex]
[tex]\Rightarrow 45-5y+10y=65[/tex]
[tex]\Rightarrow 45+5y=65[/tex]
[tex]\Rightarrow 5y=65-45[/tex]
[tex]\Rightarrow 5y=20[/tex]
[tex]\Rightarrow y=\frac{20}{5}[/tex]
[tex]\Rightarrow y=4[/tex]
Now, putting the value of [tex]y[/tex] in equation [tex](i)[/tex].
[tex]\Rightarrow x=9-4[/tex]
[tex]\Rightarrow x=5[/tex]
Hence, there are [tex]5[/tex] five dollar bills and [tex]4[/tex] ten dollar bills.
