ANSWER:
$5 and $9
STEP-BY-STEP EXPLANATION:
We have that the relationship between the battery pack and the price per battery would be:
[tex]x=1400-100p[/tex]And the equation of the daily revenue is:
[tex]R=x\cdot p[/tex]We replace the first equation in the second and we obtain:
[tex]R=(1400-100p)\cdot p[/tex]We replace the value of R and solve for p, so we can know the prices
[tex]\begin{gathered} 4500=1400p-100p^2 \\ -100p^2+1400p-4500=0 \\ -100\cdot(p^2-14p+45)=0 \\ p^2-14p+45=0 \\ (p-5)\cdot(p-9)=0 \\ p-5=0\rightarrow p=5 \\ p-9=0\rightarrow p=9 \end{gathered}[/tex]That is, when the price is $5 and $9, there is a revenue of $4500
