A and B two trains at the same time from AB two opposite, 10 hours meet Now, four hours after driving from both places, car a stops at C, and car B arrives at C nine hours later. Q: how many hours does it take for car a to go from a to B?

A and B two trains at the same time from AB two opposite, 10 hours meet Now, four hours after driving from both places, car a stops at C, and car B arrives at C nine hours later. Q: how many hours does it take for car a to go from a to B?

Car B takes the whole journey in 9 hours (1-4 / 10) = 3 / 5
It takes 9 / (3 / 5) = 15 hours for car B to complete the whole journey alone
A car from a to B to:
1 / (1 / 10-1 / 15) = 30 hours
A math problem two trains run from two places at the same time. A runs 72 kilometers per hour. B runs at 5 / 6 of a's speed
A math problem two trains run from two places at the same time. A runs 72 kilometers per hour. B's speed is 5 / 6 of a's. when they meet, a runs 114 kilometers more than B, so we can find the distance
The speed of vehicle B is 72 × 5 / 6 = 60 km / h
The time of encounter is 114 ÷ (72-60) = 9.5 hours
Distance = (72 + 60) × 9.5 = 1254km
B speed = 72 × 5 / 6 = 60 km / h
Encounter = 114 (72-56) = 19 hours
Distance = 19 × (72 + 60) = 2508km
B speed 72 × 5 / 6 = 60 km / h
Time 114 (72-60) = 9.5 hours
Distance (72 + 60) × 9.5 = 1254km
The speed of B is 72 * 5 / 6 = 60 km / h
That is, a runs 12 kilometers more per hour than B
So the formula 114 / (72-60) = 57 / 6 (hours)
Distance: 57 / 6 * (72 + 60) = 1254 (km)
Suppose: it takes t hours to meet.
Then: 72t-5 / 6 * 72t = 114 t = 9.5 (hours)
Distance between the two places: (72 + 5 / 6 * 72) * 9.5 = 1254km
Set a line x km, B line x-144 km. The speed of B is 60km / h.
x/72=x-144/60
The solution is x = 864
Be sure to understand that the time when a and B meet is equal!!!
a. B. the distance between the two places is 450 km. A and B vehicles run from the two places at the same time and meet each other after 3 hours. It is known that the speed ratio of a and B vehicles is 7:8. How many kilometers per hour can a and B vehicles walk?
450 △ 3 = 150 (km);
7÷(7+8)=7/15；
150 × 7 / 15 = 70 km;
150-70 = 80 km;
A: car a travels 70 kilometers per hour, while car B travels 80 kilometers per hour
If one root of the quadratic equation x + kx-3 is 1, what is the other root
For god horse
If one root of square + kx-3 of quadratic equation x is 1, then the other root is - 3
The motorcade transported goods and materials to the disaster area, traveling 60 kilometers per hour and 6.5 hours to the destination, and traveling 78 kilometers per hour to the destination. How long will it take them to return to their destination?
60 × 6.5 / 78 = 390 / 78 = 5 (hours) a: they can return to their departure place in 5 hours
It is known that there are 80 peach trees in the orchard, 45 pear trees and 23 apple trees? ② How many apple trees are there in the orchard?
① 80 △ 45 = 100 (trees); answer: there are 100 pear trees. ② 100 △ 23 = 150 (trees); answer: there are 150 apple trees in the orchard
A and B vehicles are running from two places 450 kilometers apart at the same time. They meet in five hours. The speed ratio of a and B is 2:7. What are the speeds of a and B vehicles?
450 / 5 = 90 (km)
2+7=9
90 / 9 = 10 (km)
10 * 2 = 20 (km) a
10 * 7 = 70 (km) B
If the lengths of the two sides of the isosceles triangle ABC are the angles of the quadratic equation x * - 5x + 6-0, then the circumference of the isosceles triangle is ?
Now the answer is two, which is right? One answer is 7 or 8, and the other is 13
x²-5x+6=0
(x-2)(x-3)=0
x=2,x=3
So the bottom of the waist is two, three or three
So perimeter = 2 + 2 + 3 = 7 or 3 + 3 + 2 = 8
(x-1)(x-6)=0
Two sides are 1 and 6, and the other side cannot be 1, because the sum of two sides is larger than the third side
So the perimeter is 6 + 6 + 1 = 13
x²-5x+6=0
(x-2)（x-3）=0
x1=2 ,x2=3
So there are two possibilities for the circumference of an isosceles triangle.
2 + 2 + 3 = 7 or 2 + 3 + 3 = 8
Hello, the one upstairs is wrong. Because (x-1) (X-6) = x & sup2; - 7x + 6 is different from the original problem.
A convoy was supposed to travel 40 kilometers per hour to reach the disaster area in 7.5 hours. In fact, it traveled 10 kilometers more per hour. How many hours did it take to reach the disaster area?
40 × 7.5 △ 40 + 10, = 300 △ 50, = 6 hours. A: it took 6 hours to get to the disaster area
It is known that there are 80 peach trees in the orchard, 45 pear trees and 23 apple trees? ② How many apple trees are there in the orchard?
① 80 △ 45 = 100 (trees); answer: there are 100 pear trees. ② 100 △ 23 = 150 (trees); answer: there are 150 apple trees in the orchard