Why do we not use closed parentheses/brackets for positive and negative infinity?

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

What is 1.5% of 120 or what number is 1.5% of 120

Xf(x) = 2x + 5 1 7 2 9 3 11 4 13 5 15 6 17 linear functions grow by equal differences over equal intervals. in the table above, what column could be added to prove this relationship?