Simplify:-12(5/6a-7/8)+1/4(3 1/2a-1 2/5)

Anyone know? is appreciated! will mark brainliest if correct!

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

If you answer 2+2 you will get over 80 points