Help! this problem is to confusing for me so please

Use set buikder notation to represent the following set: {, -2, -1, 0}

This question awards 100 ! i really don’t want to fail i will also mark you !

Marla bought a book for $12.95, a binder for $3.49, and a backpack for $44.99. the sales tax rate is 6%. find the amount of tax and the total she paid for these items