Pleas help if possible :)

Determine the difference: 3.2 × 1010 – 1.1 × 1010. write your answer in scientific notation.

Tabby sells clothing at a retail store, and she earns a commission of 6.25% on all items she sells. last week she sold a pair of jeans for $32.50, a skirt for $18.95, and 2 blouses for $14.95 each. what was tabby's total commission? a $4.15 b $5.08 c $81.35 d $348.60

Solve 3x-18=2y and 5x-6y=6 by elimination show work