what is the measure of PLEASE HELP GIVING 50 POINTS!!

OPTIONS:
90
37
143
127

In the polynomial below, what number should replace the question mark to produce a difference of squares? x2 + ? x - 36

Dexter read 11 science fiction books and 5 history books. lena read 9 science fiction books and 4 history books. compare the students’ ratios of science fiction books to history books. 1. determine the ratios’ form:    science fiction books to history books 2. write the ratios as fractions:    dexter: 115; lena: 94 3. rewrite with a common denominator. 4. compare. 5. answer the question. determine which shows the correct comparison of the ratios for this problem.

If the value of cos330°is√3/2 then find cos 165°.