What is 3x+9=6 (x-2) show work please

What basic trigonometric identity would you use to verify that sin x cos x tan x =1-cos^(2)x?

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.

:24% of students in a class are girls. if there are less than 30 students in this class, how many students are there? how many girls are there?