To find:
1. The equation that represents the total cost of any item bought in Idaho.
2. the original price of the backpack.
Solution:
1.
The sales tax in Idaho is 6%. Let the price of the item bought is p.
So, the sales tax on the item will be 0.06p. So, the total cost c is:
![\begin{gathered} c=p+0.06p \\ c=1.06p \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/azaak48ts0p0nlg4px2cgw3ju9dfqbzui8.png)
Thus, the answer is c = 1.06p.
2.
Now, the cost of backpack including the sales tax is $33.39. So, the value of c is 33.39.
Put c = 33.39 in the equation c = 1.06p and find the value of p.
![\begin{gathered} 33.39=1.06p \\ (33.39)/(1.06)=p \\ 31.05=p \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/245e2trgna6gtdf1d3m2tsmw81s5gcufok.png)
Thus, the original price is $31.05.