Determine whether the expression is a polynomial.

5x−2 − 9x + 6

(I believe it is yes, but only have 1 attempt on my homework)

A50% increase followed by 33 1/2% decrease

Find the nonpermissible replacement for binthis expression.b2/5b +5

Scores on the cognitive scale of the bayley-scales of infant and toddler development range from 1 to 19, with a standard deviation of 3. calculate the margin of error in estimating the true mean cognitive scale score, with 99% confidence, if there are 12 infants and toddlers in a sample.