Math problems in the second year of junior high school The gas storage capacity of the Ping an gas s

You didn't give the line in Figure 12?

Solution: (1) As can be seen from the figure, 10,000-2,000=8,000 cubic meters of natural gas were injected on Sunday

2) When x>= , let the analytic formula of the function of the gas storage capacity y (cubic meter) and the time x (hour) in the gas storage tank be:

y=kx+b ( is constant, and k≠0 ), and its image passes through the point (,10000), 8000), and the solution is k=-200

b=10100

Therefore, the analytical formula of the function is as follows: y=-200x+10100(3).

To refuel 18 cars need 18 * 20 = 360 (cubic meters), gas storage capacity is 10000-360 = 9640 (cubic meters), so there are: 9640 = -200x + 10100, the solution: x = , and from 8:00 to 10:30 difference hours, obviously have: < Therefore, the 18th car can be refilled before 10:30 on the same day

1) 10000-2000=8000m Hold the rock potato jujube bend, A: 8000m 2) Y=200x

3) 2*200=400m segment.

400 20 = 20 cars.

20 vehicles are more than 18 vehicles.

A: Yes.

(1) As can be seen from the figure, 10,000-2,000 = 8,000 cubic meters of natural gas were injected on Sunday;

2) When x>= , let the analytic formula of the function of the gas storage capacity y (cubic meter) and the time x (hour) in the gas storage tank be:

y=kx+b ( is constant, and k≠0 ), and its image passes through the point (,10000), 8000), and the solution is k=-200

b=10100

Therefore, the analytical formula of the function is as follows: y=-200x+10100(3).

To refuel 18 cars need 18 * 20 = 360 (cubic meters), gas storage capacity is 10000-360 = 9640 (cubic meters), so there are: 9640 = -200x + 10100, the solution: x = , and from 8:00 to 10:30 difference hours, obviously have: < Therefore, the 18th car can be refilled before 10:30 on the same day

I think it was inflated from 8:30, 8:30+:30+2 hours and 18 minutes = 10:48, 10:48 10:30, so it can't.

(1) 10000-2000=8000m, A: 8000m (2) y=200x

3)2*200=400m³

400 20 = 20 cars.

20 cars more than 18 cars A: Yes.

(1) 10000-2000=8000m, A: 8000m (2) y=-200x+10100

3)2*200=400m³

400 20 = 20 cars.

You can finish filling up by 10:30 on the day.

Solution: (1) As can be seen from the figure, 10,000-2,000=8,000 cubic meters of natural gas were injected on Sunday2) When x>= , let the analytic formula of the function of the gas storage capacity y (cubic meter) and the time x (hour) in the gas storage tank be:y=kx+b ( is constant, and k≠0 ), its image passes through the point (,)8000), and the solution is k=-200 b= so the analytical formula of the function is :

y=-200x+ (3) can refuel 18 cars need 18*20=360 (cubic meters), gas storage is -360=9640 (cubic meters), so there is: 9640=-200x+, solution: x= , and from 8:

There is a difference of hours from 00 to 10:30, apparently there are: < so the 18th car is at 10:0 on the same day

You can finish filling up before 30

The question says that from 8 o'clock to 8:30 o'clock, the gas company fills the gas storage tank of the Ping An gas station with natural gas (that is, after 8:30) before filling the car, why is the third question answered from 8 o'clock?

Solution: (1) As can be seen from the figure, 10,000-2,000=8,000 cubic meters of natural gas were injected on Sunday

2) When x>= , let the analytic formula of the function of the gas storage capacity y (cubic meter) and the time x (hour) in the gas storage tank be:

y=kx+b ( is constant, and k≠0 ), and its image passes through the point (,10000), 8000), and the solution is k=-200

b=10100

Therefore, the analytical formula of the function is y=-200x+10100

3) can be 18 cars to refill the gas need 18 * 20 = 360 (cubic meters), gas storage capacity is 10000-360 = 9640 (cubic meters), so there are: 9640 = -200x + 10100, the solution: x = , and from 8:00 to 10:30 difference hours, obviously have: < Therefore, the 18th car can be refilled before 10:30 on the same day

4)-200x+10100 ≥8000

200x≥-2100

x< = 8,000 cubic meters of gas in the gas storage tank of the gas station on Sunday (8:00--18:30).

(1) 10000-2000=8000m, A: 8000m (2) y=200x (3) 20 cars more than 18 cars A: Yes, you must give me extra points.

(1) Let the functional relationship between the gas storage capacity y (cubic meter) and time x (hour) of the gas station from 8:00 to 8:30 be y1

kx+b, according to the image to get a straight line (0, 10000) and (, 9700), substituting to get:

10000＝b

9700, solution: k=-600, b=10000, 8:00-8:30 gas storage capacity y (cubic meter) and time x (hour) of the gas station function relationship is y1

600x+10000；

Let the relationship between the gas storage capacity y (cubic meter) and time x (hour) of the gas station after 8:30 be y2

ax+c, according to the image, the straight line (,5700) and (,9700) are obtained, and the substitution obtains:

9700, solution: a=-1000, c=10200, 8:00-8:30 gas storage capacity y (cubic meter) and time x (hour) of the gas station function relationship is y2

1000x+10200；

2) 30 vehicles need to consume gas for 30 20 = 600 (cubic meters);

10000-600=9400, as can be seen from the figure, it cannot be added before 8:30;

Substitute y=9400 into y=10200-1000x, and solve x=hours); , it is impossible to fill up before 8:42 on the same day;

3) N cars need to fill 20n cubic meters of gas, and substitute y=10000-20n into y1

600x+10000 gets: x=n

30, substitute y=10000-20n into y2

1000x+10200 gets: x=1

n50，∴n

n)=1, solution: n=90