Use matrix operations to compute the total profit at each store in January.?

In January, the Left Coast Bookstore chain sold 700 hardcover books, 1,400 softcover books, and 2,400 plastic books in San Francisco; it sold 400 hardcover, 500 softcover, and 500 plastic books in Los Angeles. Now, hardcover books sell for $30 each, softcover books sell for $10 each, and plastic books sell for $15 each. Suppose that each hardcover book costs the stores $10, each softcover book costs $5, and each plastic book costs $10. Use matrix operations to compute the total profit at each store in January? SAN FRANSISCO= ??? LOS ANGELES= ???