DOES ANYONE KNOW HOW TO DO THIS PLEASE NO LINK TY

Can someone me with the property questions for 12 13 and 14 plz

Which expression do you get when you eliminate the negative exponents of 4a^2 b^216a^-3 b

Recall that the owner of a local health food store recently started a new ad campaign to attract more business and wants to know if average daily sales have increased. historically average daily sales were approximately $2,700. the upper bound of the 95% range of likely sample means for this one-sided test is approximately $2,843.44. if the owner took a random sample of forty-five days and found that daily average sales were now $2,984, what can she conclude at the 95% confidence level?