Which of the following is the product of the rational expressions shown below?
3x/x+1 * x/x-7

Find the value of the cosine for angle a

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.

Ineed the solution to this problem and the steps.