1. There is 50L gasoline in the fuel tank of a car, the fuel consumption of the car is 10L every 100km, the distance of the car is x, and the remaining quantity of the mailbox is y. write the relationship between Y and X 2. The capacity of a car's fuel tank is 30L, and there is 10L gasoline in the tank. Now add XL gasoline. If the price of gasoline per liter is 5.99 yuan, find the functional relationship between Y (yuan) and X (L). Is it y = 5.99 (10 + x) for a pair of answers

1. There is 50L gasoline in the fuel tank of a car, the fuel consumption of the car is 10L every 100km, the distance of the car is x, and the remaining quantity of the mailbox is y. write the relationship between Y and X 2. The capacity of a car's fuel tank is 30L, and there is 10L gasoline in the tank. Now add XL gasoline. If the price of gasoline per liter is 5.99 yuan, find the functional relationship between Y (yuan) and X (L). Is it y = 5.99 (10 + x) for a pair of answers

1. Y = 50-10 x
2. No, it should be y = 5.99x [0 ≤ x ≤ 20]

A car's fuel tank contains 50 liters of gasoline, and the car's fuel consumption is 20 liters when driving 200 km. If the fuel volume in the fuel tank is y liters, the driving distance is x km
(1) Write the functional relationship between Y and X (2) find out the value range of X (important process) (3) draw the function diagram

(1) Solution: y = kx
200/20=10km/L
10x=50-y Y=50-10x
（2）50-10x≥0
x≤5
(3) Using the analytic formula, the coordinate connection of the intersection point with X axis and Y axis is obtained respectively = = note that this function image can only be in the first quadrant

If the fuel tank of a car is filled with 45 liters of gasoline at a time, it is feasible to drive y km. Suppose that the car consumes x liters of fuel every 100 km, then the analytic function of Y with respect to X is______ ．

∵ a car consumes x liters of fuel every 100 kilometers, 1 liter of gasoline can travel 100x kilometers, y = 45 × 100x = 4500X

There are 90 liters of gasoline in the fuel tank of a car, and the fuel consumption of the car is 4.5 liters per 60 km. Suppose the distance of the car is x km, and the remaining fuel in the fuel tank is y
1. Write the functional relationship between Y and X,
2. After driving 200 kilometers, how many kilometers can the car drive at most before it has to refuel?

0.075l per km
（1）y＝90－0.075x
（0＜＝x＜＝1200）
（2）y＝90－0.075×200
y＝90－15
x＝75
75÷0.075＝1000km