The two vehicles run from two places 90 kilometers apart at the same time. After 23 hours, the two vehicles meet on the way?

The two vehicles run from two places 90 kilometers apart at the same time. After 23 hours, the two vehicles meet on the way?

(90-60 × 23) △ 23 = (90-40) △ 23 = 50 △ 23 = 75 (km) a: car B travels 75 km per hour

In Pythagorean theorem, the square of a + the square of B = the square of C
Step by step

Dim I as long, j as long, K as long for I = 1 to 20 for J = I to 20 for k = J to 20 If I ^ 2 + J ^ 2 = k ^ 2 then print I; J; K next K next J next I all the answers that meet the requirements are: 3,4,5,12,13,6,8,10,8,15,17

The two trains of Party A and Party B depart from the two places 500 km apart at the same time, but they do not meet each other after 4 hours, and the distance is still 20 ㎞. It is known that car a travels every hour, and how much does car B travel every hour?

（1）（500-20）÷4-65,
=480÷4-65,
=120-65,
=55 km;
A: car B travels 55 kilometers per hour

If the average of data a, B, C, D and E is 6, what is the average of data a + 1, B + 2, C + 3, D + 4 and E + 5?

a+b+c+d+e=6*5=30
(a+1+b+2+c+3+d+4+e+5)/5=(30+1+2+3+4+5)/5=9

The sum of 25 consecutive even numbers is 2000. What is the smallest even number?

Ah
Divide 1000 by 25 to know the average number of each number, that is, the corresponding number in the middle, that is, the 23rd number
1000/25=40
That is to say, the two even numbers before and after the thirteenth add up to 40 * 2 = 80 (38 + 42 = 80)
The number before and after the thirteenth number add up to 80 (36 + 44 = 80)
And so on to the first number, there are 13-1 = 12 numbers, because they are even numbers, so they should be separated by 2 * 12 = 24 digits
So it should be 40-24 = 16. The last number is 80-16 = 64
Above, complete, check, correct
I am a student, what's wrong with the amount of m to say

There is a three digit number. The three numbers are all three different prime numbers within 10 and can be divided by 2 and 3 at the same time. What is the maximum and minimum of the three digit number

Prime numbers within 10 have 2, 3, 5 and 7, which can be divided by 3. The last digit must be 2,
The first digit of the largest number must be 7. 7 () 2 can be divided by 3, and () is 3, so the largest number is 732
The first place of the minimum number must be 3. 3 () 2 can be divided by 3, and () is 7, so the minimum number is 372

The fast train and the slow train run in opposite directions. After 2 hours, they meet at the distance of 3 km from the midpoint. The fast train runs 75 km per hour, and the slow train runs how many km per hour?

Let the distance be 2x
Express x + 3
Slow x-3
X+3=75*2=150
The local distance is 144
144/2=72KM/H

As shown in the figure, in the quadrilateral ABCD, AB is parallel to CD, BC is parallel to AD. what is the size relationship between angle A and angle c, angle B and angle D? Please explain your reasons

Because ABCD is a parallelogram, angle a + angle d = 180 degrees, angle a + angle B = 180 degrees, so angle d = angle B and angle a = angle c can be deduced

A pile of coal has four fifths of a ton. One twentieth of it is used. How many tons are used?

4/5x1/20=1/25=0.04

Mean inequality requires "one positive two definite three equal", if not positive how to do?
For example, y = t + 5 + 4 / T, and t ≥ - 4,

This problem is not special, can only use "double hook function" to do
Draw the image of F (x) = x + 4 / x + 5 (x ≥ - 4),
You will find that it has neither a minimum nor a maximum
In other words, its minimum is - ∞ and its maximum is + ∞