THE Lenghts of the rectangle have been measured to the nearest tenth of a metre. Work out the upper bound for the perimeter and lower bound for the area

In simplified exponential notation, the expression a^2•a^-3•a 1/a 0

Any is very appreciated! (picture is provided below)not sure how to do this at all won't lie

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