Respuesta :
Explanation
Step 1
Set the equations:
let x represents the number of five dollars bills
let y represents the number of ten dollars bill
so
a)It contains twice as many five's as ten's,so
[tex]x=2y\Rightarrow equation(1)[/tex]b)and the total amount of money in the cash register is 720 dollars,so
[tex]5x+10y=720\Rightarrow equation(2)[/tex]Step 2
solve the equations:
[tex]\begin{gathered} x=2y\Rightarrow equation(1) \\ 5x+10y=720\Rightarrow equation(2) \end{gathered}[/tex]a)replace the y value from eq(1) into equation(2)
hence
[tex]\begin{gathered} 5x+10y=720\Rightarrow equation(2) \\ 5(2y)+10y=720 \\ 20y=720 \\ divide\text{ both sides by 20} \\ \frac{20y}{20}=\frac{720}{20} \\ y=36 \end{gathered}[/tex]b) replace the y value into equation(1) to obtain x
[tex]\begin{gathered} x=2y \\ x=2(36) \\ x=72 \end{gathered}[/tex]therefore,
the number of five dollars bill is : 72
the number of ten dollars bill is : 36
I hope this helps you
