The number of science and technology books purchased by school libraries is 3/7 of that of story books, and the total number of science and technology books and story books purchased is 1500. How many science and technology books do you buy? Assuming that X storybooks are purchased, according to the number of science and technology books, which is 3.7 times that of storybooks, it can be concluded that 3 7 x science and technology books have been purchased, and the equation can be obtained according to the meaning of the questions.

x+ 3 7 x= 1500

x = 1050；

37 x = 37 x1050 = 450 (volume);

A: I bought 450 science and technology books.