SOMEONE PLZZZ HELP ME WITH THIS QUESTION!! I'd be immensely grateful :/

The equation x2 – 1x – 90 = 0 has solutions {a, b}. what is a + b?

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).

Find an bif a = {3, 6, 9, 12) and b = {2, 4, 6, 8, 10).