Mike can plow a field in 12 hours and his brother Phil can plow it in 15 hours. How long will it take them to plow it if they use two plows and work together?

Quick! a survey of 57 customers was taken at a bookstore regarding the types of books purchased. the survey found that 33 customers purchased mysteries, 25 purchased science fiction, 18 purchased romance novels, 12 purchased mysteries and science fiction, 9 purchased mysteries and romance novels, 6 purchased science fiction and romance novels, and 2 purchased all three types of books. a) how many of the customers surveyed purchased only mysteries? b) how many purchased mysteries and science fiction, but not romance novels? c) how many purchased mysteries or science fiction? d) how many purchased mysteries or science fiction, but not romance novels? e) how many purchased exactly two types of books?

Which inequality is equivalent to -3x < -12? x < 4 , x < -4 , x > 4, x > -4

What is the effect on the graph of the function f(x) = x2 when f(x) is changed to f(x) − 4?