NEW YORK (AP) ― Apple Inc. on Thursday launched its attempt to make the iPad a replacement for a satchel full of textbooks by starting to sell electronic versions of a handful of standard high-school books.

The electronic textbooks, which include “Biology” and “Environmental Science” from Pearson and “Algebra 1” and “Chemistry” from McGraw-Hill, contain videos and other interactive elements.

But it’s far from clear that even a company with Apple’s clout will be able to reform the primary and high-school textbook market. The printed books are bought by schools, not students, and are reused year after year, which isn’t possible with the electronic versions. New books are subject to lengthy state approval processes, making the speed and ease with which ebooks can be published less of an advantage.

Major textbook publishers have been making electronic versions of their products for years, but until recently, there hasn’t been any hardware suitable to display them. PCs are too expensive and cumbersome to be good e-book machines for students. Dedicated e-book readers like the Kindle have small screens and can’t display color. IPads and other tablet computers work well, but iPads cost at least $499. Apple didn’t reveal any new program to defray the cost of getting the tablet computers into the hands of students.

All this means textbooks have lagged the general adoption of e-books, even when counting college-level works that students buy themselves. Forrester Research said e-books accounted for only 2.8 percent of the $8 billion U.S. textbook market in 2010.

Pearson PLC of Britain and The McGraw-Hill Cos. of New York are two of the three big companies in the U.S. textbook market. The third, Boston-based Houghton Mifflin Harcourt, also plans to supply books to Apple’s store, but none were immediately available.

The new textbooks are legible with a new version of the free iBooks application, which became available Thursday.

The textbooks will cost $15 or less, said Phil Schiller, Apple’s head of marketing. He unveiled the books at an event at New York’s Guggenheim Museum. Schools will be able to buy the books for its students and issue redemption codes to them, he said.

Albert Greco, a professor of marketing at Fordham University in New York and a former high-school principal, said schools would need to buy iPads for its students if it were to replace printed books.

It wouldn’t work to let students who can afford to buy their own iPads use them in class with textbooks they buy themselves, alongside poorer students with printed books.

“The digital divide issue could be very embarrassing. Because if you don’t have the iPad, you can’t do the quiz, you don’t get instant feedback ... that is an invitation for a lawsuit,” Greco said. “I would be shocked if any principal or superintendent would let that system go forward.”