Given that x is an integer, and X + 2 / 3 + "2 / 3-x" + "2x / 9 of X + 18" is an integer, find all the values of X that meet the conditions

Given that x is an integer, and X + 2 / 3 + "2 / 3-x" + "2x / 9 of X + 18" is an integer, find all the values of X that meet the conditions

Let's first divide: (2x + 6) / (x ^ 2-9) = 2 / (x-3), the result is an integer, so x is 1,2,4,5

The distance between a and B is 240 km. Buses drive from a to B at the speed of 80 km per hour, and cars drive from B to a at the speed of 100 km per hour
The bus starts at 8 a.m. and the car just meets at 100 kilometers away from ground A. when should the car start?

When we met, the bus traveled 100 km, 100 △ 80 = 1.25 hours, the sedan 240-100 = 140 km, 140 △ 100 = 1.4 hours; the car traveled 1.4-1.25 = 0.15 hours = 9 minutes more than the bus, that is, the car left 9 minutes earlier than the bus

In RT triangle ABC, if a: B = 4:3 and C = 10, then A.B
In RT triangle ABC, ∠ C = 90 degree
If a: B = 4:3, C = 10, find A.B
If a: C = 5:13, B = 24, find A.C
If B = 6, C-A = 2, find A.C
If B = 11, C = 61, find a

According to Pythagorean theorem, C square = a square + b square,
1. Let a = 4x, B = 3x, then (4x) ^ 2 + (3x) ^ 2 = 100, x = 2, a = 8, B = 6
2. Let a = 5x, C = 13X, (13X) ^ 2 = 25X ^ 2 + (24) ^ 2, x = 2, a = 10. B = 26
3,a^2+6^2=(a+2)^2,a=8,b=10
4,(11)^2+a^2=(61)^2,a=60

Car a and car B drive from station a and B at the same time. Car a travels 40 kilometers per hour. Car B travels 5 kilometers faster than car A. three hours later, the two cars are 18 kilometers apart
How many kilometers are there between stations a and B?

The speed of car a is 40 km / h, and the distance covered in 3 hours is 40 * 3 = 120 km
If the speed of car B is 5 km faster than that of car a, the speed is 40 + 5 = 45 km / h, and the distance covered in 3 hours is 45 * 3 = 135 km
Three hours later, the distance between the two vehicles is 18 km, so the distance between the two vehicles is 120 + 135 + 18 = 273 km

It is known that a, B and C are the three sides of △ ABC, and the square of (B-C) = (- 2a-b) (C-B)

Take apart B ^ 2-2bc + C ^ 2 = (2a + b) (B-C) B ^ 2-2bc + C ^ 2 = 2ab-2ac + B ^ 2-bc-bc + C ^ 2 = 2ab-2acc ^ 2-bc-2ab + 2Ac = 0C (C-B) + 2A (C-B) = 0 (C-B) (c + 2a) = 0, so C-B = 0 or C + 2A = 0. Obviously, because C A is greater than 0, C + 2A cannot be equal to 0, so C-B = 0b = C, so triangle ABC is isosceles

A correspondent rides a motorcycle to deliver the documents within the prescribed time. His speed is 36 kilometers per hour. As a result, he arrives 20 minutes earlier. If he is 30 kilometers per hour, he is 12 minutes late? What's the distance?

Suppose the specified time is x hours, according to the meaning of the question: 36 (X-13) = 30 (x + 15), the solution is: x = 3  36 × (3-13) = 36 × 83 = 96 km a: the specified time is 3 hours, and the distance is 96 km

6.5 (580-6y) △ 8 + 4.5y = 460
Ten gold coins for correct answer!

Multiply the equation left and right by 8 at the same time

Two cars carry 5 / 8 of a batch of goods in five hours. How many parts of this batch of goods do one car transport in one hour

4 cars per hour: 5 / 8 △ 5 = 1 / 8
One car and one hour transportation: 1 / 8 △ 4 = 1 / 32

If the solution of the equation 9x-2 = KX + 7 of X is a natural number, then the value of integer k is______ ．

By changing the term, 9x-kx = 2 + 7 and merging the similar term, (9-k) x = 9, because the equation has a solution, so K ≠ 9, then the coefficient is obtained, x = 99 − K. also ∵ the solution of the equation 9x-2 = KX + 7 about X is a natural number, and the value of ∵ K can be: 0, 6, 8. The corresponding natural number solutions are: x = 1, x = 3, x = 9

When we transport Huangsha by truck, the first time we transport 1 / 2 tons, the second time we transport a quarter of the first time, and there are 3.5 tons left. How many tons of Huangsha are there altogether

1 / 2 × 1 / 4 = 1 / 8 (ton)
1 / 2 + 1 / 8 + 3.5 = 4.125 (ton)