A notebook costs $4.50 plus sales tax.after sales tax,the notebook is $4.86 what is the sales tax rate

The sales tax rate would be 8%.

To find how much you spent on tax in the total, you'd begin by subtracting the pre-tax notebook from the after tax notebook.

4.86 - 4.50 = 0.36

So now we know that you spent 36 cents on tax. From there, we'd divide our money spent on tax by our pre-tax total. 

0.36 ÷ 4.50 = 0.08

This means that the sales tax is 8%. 

Hope I could help!