PLEASE HELP THIS IS REALLY IMPORTANT
3. Simplify each expression. Show as much work as possible for each question for full credit. Write each answer in standard form.

a) (-5 +x)(x+4) (Show your work) (5 points)
b) Is the product of -5 +x and x+4 equal to the product of 5+x and x-4? Explain your answer. (Show your work to prove your answer) (2 points)
c) (2+5)(3²+4−3) (Show your work) (5 points)

Atextile fiber manufacturer is investigating a new drapery yarn, which the company claims has a mean thread elongation of 12 kilograms with a standard deviation of 0.5 kilograms. the company wishes to test the hypothesis upper h subscript 0 baseline colon mu equals 12 against upper h subscript 1 baseline colon mu less-than 12 using a random sample of n equals 4 specimens. calculate the p-value if the observed statistic is x overbar equals 11.8. round your final answer to five decimal places (e.g. 98.76543).