The two trains of Party A and Party B start from the same city and run in opposite directions. The speed of train a is 36 km / h, and that of train B is 48 km / h. It is known that train a starts 2 hours earlier than train B After how many hours, B catch up with a

The two trains of Party A and Party B start from the same city and run in opposite directions. The speed of train a is 36 km / h, and that of train B is 48 km / h. It is known that train a starts 2 hours earlier than train B After how many hours, B catch up with a

Let's catch up with B in X hours
36（X+2）=48X
X=6
In fact, the topic is wrong. It's not opposite. It should be in the same direction. Opposite is opposite
The length of train a and train B are 144m and 180m, and train a runs 4m more per second than train B. the two trains are facing each other, and it takes 9s from meeting to staggering. What's the speed of the two trains?
Suppose car B travels XM per second, then car a Travels (x + 4) m per second. According to the meaning of the question, we get: 9 (x + X + 4) = 144 + 180, sort out: 2x = 32, solve: x = 16, then car a travels 20m per second, car B travels 16m per second
The length of the two trains is 148 meters and 180 meters respectively. Car a runs 5 meters more per second than car B. It takes 8 seconds for the two trains to run in opposite directions. What's the speed of the two trains?
It's a formula
If the speed of vehicle B is V, the speed of vehicle a is V + 5
(148+180)/（V+V+5)=8
328 = 16V + 40, v = 288 / 16 = 18, B is 18m / s, a is 18 + 5 = 23
2 pieces of clothes, 2 bottles of mineral water, a total of 44 yuan. 1 piece of clothes, 1 bottle of mineral water, a total of 26 yuan
Let X be clothes, y be mineral water, and set up equations
The speed of the freight car is 3 / 4 of that of the passenger car. When the two cars leave from a and B at the same time and meet at a distance of six kilometers from the midpoint, how many kilometers is the distance between the two stations
I'm in a hurry
Because the freight car is 3 / 4 of the speed of the passenger car, that is, the speed of the freight car: the speed of the passenger car = 3:4, when they meet, because they travel the same time, so their driving distance ratio is 3:4, so the passenger car takes 4 / (3 + 4) = 4 / 7 of the whole journey, half of the journey is 1 / 2, 6 km corresponds to 4 / 7-1 / 2 = 1 / 14, the comprehensive formula is 6 / [4 /]
The answer is 42km
Let t be the meeting time and X be the speed
If the train speed is three fourths of X, then in t time, the bus runs 6km more than the truck
So, 1 / 4x * t = 6, t = 24 / X
S = (t * V truck) + (t * V bus) = 24 / X * 3x / 4 + 24 / X * x = 42 km
If the speed of passenger cars is 1, the speed of freight cars is 3 / 4. When the passenger cars meet, it takes the same time (s + 6000) / 1 = (s-6000) / (3 / 4) s = 42000 2S = 84000 to walk s-6000
Mixed operation of five rational numbers with power,
3+2^2×（-1/5）
Original formula = 3 + 4 × (- 1 / 5)
=3-4/5
=11/5
18-6÷（-2）×（-1/3）
Original formula = 18 - (- 3) × (- 1 / 3)
=18-1
=17
（-3）^2×[-2/3+（-5/9）]
Original formula = 9 × (- 11 / 9)
=-11
8+（-3）^2×（-2）
Original formula = 8 + 9 × (- 2)
=8-18
=-10
100÷（-2）^2-（-2）÷（-2/3）
Original formula = 100 △ 4-3
=25-3
=22
36×（1/2-1/3)^2
Original formula = 36 × (1 / 6) ^ 2
=36×（1/36）
=1
12.7÷（-8/19）×0
The original formula is 0
4×（-3）^2+6
Original formula = 4 × 9 + 6
=36+6
=42
（-3/4）×（-8+2/3-1/3)
Original formula = (- 3 / 4) × (- 8 + 1 / 3)
=（-3/4）×（-23/3)
=23/4
（-2）^3-13÷（-1/2）
Original formula = (- 8) - (- 26)
=18
0-2^3÷（-4）^3-1/8
Original formula = 0-8 ÷ (- 64) - 1 / 8
=0+1/8-1/8
=0
(-2)^3×0.5-（-1.6）^2÷(-2)^2
Original formula = (- 8) × (1 / 2) - (- 8 / 5) ^ 2 △ 4
=（-4）-（64/25）÷4
=（-4）-16/25
=-116/25
(-3/2)×[（-2/3）^2-2]
Original formula = (- 3 / 2) × (4 / 9-2)
=（-3/2）×（-14/9）
=7/3
[(-3)^2-(-5)^2]÷（-2）
Original formula = (9-25) / (- 2)
=（-16）÷（-2）
=8
16÷（-2）^3-（-1/8）×（-4）
Original formula = 16 △ (- 8) - 1 / 2
=-2-1/2
=-5/2
The construction site needs 400 m of sand and stone. If it is transported by 4 T truck, how many trucks are needed? (density = 2.6 × 10 kg / M)
As the name suggests, the most important difference between a horse drawn carriage and a carriage is that the handle of the carriage is welded with iron
A bottle of mineral water is 595; a box of milk is 250; the volume of a classroom is about 200; the volume of a desk drawer is 25
Come on, good answer, good reward
Keywords milliliter; milliliter; cubic decimeter; cubic decimeter;
Ml, ML, m3, l
595 ml
250 ml
200 square meters
25 square decimeters
Milliliter cubic meter cubic decimeter
ml,ml,m^3,dm^3
The ratio of the speed of the freight car to that of the bus is 3:4. The two cars leave from a and B at the same time and meet at the midpoint of 6km. How many kilometers are there between a and B?
Suppose a goes 3x, then B goes 4x
The midpoint is (3 + 4) x / 2 = 3.5x
4X-3.5X=0.5X=6
X=12
The whole journey is (3 + 4) x = 84 km
I need a lot of mixed operations of rational numbers, as well as power
Don't make a fool of yourself