Which expression is equivalent to 18 – 20?

The parabola opens: y=√x-4 (principal square root) up down right left

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.

0if x and y vary inversely and y=6 as x=7, what is the constant of variation?