Let the unit price of exercise book be X yuan, and the equation (5x+0.1=1x = 0.18 yuan) can be obtained.
2. Warehouse A stores 200 tons of coal and warehouse B stores 70 tons. If A transports 15 tons per day and B transports 25 tons per day, how many days will B be twice as many as A?
Assuming that after X days, B is 1 times more than A, then A has (1 10) tons of coal and B has (220) tons, and the equation can be obtained.
(2(200- 15x)=70+25x)
Xiang Ming is 37 years younger than his uncle. Two years ago, his uncle was four times as old as Xiao Ming two years later. How old is Xiaoming this year?
Suppose Xiaoming is X years old this year, then his uncle is (x+37) years old this year, his uncle was (x+37-2) two years ago, and Xiaoming was (9+2= 1 1) two years later.
The equivalent relationship in this question is (his uncle was four times as old as Xiao Ming two years ago)
Equation ((x+37-2)/(x+2)=4) can be obtained.