A bookstore stipulates that if you buy more than 100 books of the same type, you can collect 90% of the payment. When the customer buys two kinds of books, A and B, the number of B books is 3/5 of A books, and only A books get the discount. , where the price paid for buying a book of type A is twice the amount paid for a book of type B. It is known that each book of type B is 10.5 yuan, how much is the price of each book of type A before the discount (suggested equation)
某书店规定凡购买同一种书书100本以上，可按90%收款，顾客买了甲乙两种书，乙种书的本数是甲种书的(3/5)，只有甲种书得到优惠，其中买甲种书付的钱是买乙种书付的钱的2倍，已知乙种书每本10.5元，优惠前甲种书每本多少元(建议方程)
<gadget id="calculator">12.6 / 0.9</gadget>
<output>14</output>

<result>14</result>