Given:
Daniel bought a bicycle for $80 and a helmet for $20.
Sales tax = 5%
To find:
The total amount of both items including tax.
Solution:
Price of bicycle (excluding tax)=
![\$80](https://img.qammunity.org/2022/formulas/mathematics/high-school/bcc7fqhxlss0qhvvl45qyqt1g3ktqc4jx9.png)
Price of helmet(excluding tax) =
![\$20](https://img.qammunity.org/2022/formulas/mathematics/high-school/dium6tbcoqzi5dqgsjln2yu7b340xdb05y.png)
Price of both items =
![\$80 + \$20](https://img.qammunity.org/2022/formulas/mathematics/high-school/upova0rg0yzr3lspz8a6l19nrkcw2iecxa.png)
=
![\$100](https://img.qammunity.org/2022/formulas/mathematics/high-school/r2gxe6jbee9wsixz5o991rjewl4f0btxlb.png)
Now, the sales tax is 5%. So,
Price of both items (including tax) =
![\$100+(5)/(100)(\$100)](https://img.qammunity.org/2022/formulas/mathematics/high-school/9rq5ezkygc1wjvuqlu52iswm66dt0nvnan.png)
=
![\$100+\$5](https://img.qammunity.org/2022/formulas/mathematics/high-school/6ptgx219kztwt4p9jvo3nw06is9lltt4t2.png)
=
![\$105](https://img.qammunity.org/2022/formulas/mathematics/high-school/x1mow3fqslk5f9h3f8v0yq2zbwonqgux60.png)
Therefore, the Daniel pays $105 for the two items, including tax.