Update 1: very gd fast+hard

Update 2: enough a_a

The sum of two digits is 9, and one digit is less than a quarter of the ten digits. This number =? Let this number = xy x+y = 9 ... (1) 4x-1= y ... (2) Generate (2) Input (1) x+4x-1= 95x =1.

Y=7, so the number is 27. After releasing five pigs and buying back two horses, Xiaoming's cash increased by 8000 dollars. If your cash increases by 10000 USD after releasing 9 pigs and buying back 4 horses, (a) the price of a pig and (b) the price of a horse, let the pig be worth X yuan.

Horse value Y element 5x-2y = 8000 ... (1) 9x-4y =10000 ... (2) (1) * 2-(2)10x-9x =/kloc-. Kloc-0/ 1000 So the price of pigs = 6000 dollars, and the price of horses = 165438 dollars.

Reference: I