Hello!
First, let's calculate the tax rate and the amount of the tips. Then, we'll add these values to the total bill.
Tax Rate: 8.25%
[tex]\begin{gathered} \frac{87}{x}=\frac{100\%}{8.25\%} \\ \\ 100x=87\times8.25 \\ 100x=717.75 \\ x=\frac{717.75}{100} \\ x=7.1775\cong7.18 \end{gathered}[/tex]Tips: 15%
[tex]\begin{gathered} \frac{87}{x}=\frac{100\%}{15\%} \\ \\ 100x=87\times15 \\ 100x=1305 \\ x=\frac{1305}{100} \\ \\ x=13.05 \end{gathered}[/tex]Total bill:
[tex]87+7.18+13.05=\$107.23[/tex]