Paulina works out with a 2.5 kilogram mass. what is the mass of the 2.5 kilogram mass in grams

Evaluate the given expression if m=45 |-3m|

Me because some of question i don’t understand

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