Solving equation 5 (X-12) = 2x

Solving equation 5 (X-12) = 2x

5(x-12)=2x
5x-5*12=2x
5x-2x=5*12
3x=60
x=20

Solve the equation y = 12 / x, y = 2x / 3 + 6

You take equation 1 into equation 2 and get:
12/x=2x/3+6;
Multiply both sides by 3x
36=2x²+18x；
Simplification is achieved
x²+9x-18=0；
So x = (- 9 ± 3 √ 17) / 2;
So if you take in Formula 1, you get y,

If the difference between the decimal point of a decimal and the original number is 34.65, then the original number is______ ．

35 × 100 = 35 A: the original number is 35, so the answer is: 35

A passenger car and a train run from both sides at the same time. The speed of passenger car is 120 km / h, and that of freight car is 80 km / h. when they meet, there are more passenger cars than freight cars
40 km. Find the time of meeting and the distance between a and B

Encounter time = 40 ÷ (120-80) = 1 (hour)
Distance between a and B = 120 + 80 = 200 (km)

Is the proposition "for any real number x, there is a real number y, so that x + Y > 0" a universal proposition or a special proposition? What is its negative form?
High school new curriculum learning guidance high school mathematics problems, please help solve, thank you!

any x (exist y, x+y>0)
Negation 1: exist x not (exist y, x + Y > 0)
Negation 2: any x (Any Y, exist x + y)

The distance between station a and station B is 1280 km. After adopting the "harmony" EMU to increase the speed, the train speed is 3.2 times of the original speed, and the time from station a to station B is shortened by 11 hours, so the speed of the train after increasing the speed can be calculated

Suppose the speed of the train before the speed increase is x km / h, then the speed after the speed increase is 3.2X km / h. according to the meaning of the question, we can get: 1280 x-12803.2x = 11. Solving this equation, we can get: x = 80. After the test, x = 80 is the root of the equation listed. 80 × 3.2 = 256 (km / h). Answer: the speed of the train after the speed increase is 256 km / h

The average number of the three numbers is 36, and the ratio of the three numbers is 1 / 2:2 / 3:5 / 6. The maximum number of the three numbers is 36

The sum of the three numbers is: 3 * 36 = 108
The ratio of the three numbers is 3:4:5 (at the same time expanded by 6 times)
The maximum number is 108 * 5 / 12 = 45

The distance between a and B is equal to the distance between B and C. the speed of B is 80% of the speed of A. It is known that B starts 11 minutes earlier than a, but stops at B for 7 minutes, and a keeps on driving to C. finally, B arrives at C 4 minutes later than a. then, after B starts, B starts______ The first car will overtake the second car in 15 minutes

Try to find out such a four digit number. The square of the sum of the two digits formed by the first two digits and the last two digits is exactly equal to the four digit number

Suppose that the front and back two digit numbers are x, y, ■ (x + y) 2 = 100x + y.x2 + 2 (y-50) x + (y2-y) = 0.b2-4ac = 4 (y-50) 2-4 (y2-y) = 4 (2500-99y) ≥ 0, then y ≤ 252599, when y ≤ 252599, the original equation has a solution. ■ x = − 2 (Y − 50) ± △ 2 = 50-y ± 2500 − 99y, ■ 2500-99y must be a complete square, and the last digit of the complete square can only be 0; 1; 4; 5; 6 The number of digits of 9. X is 2, and Y is 2. Y = 25, x = 30 or 20, and the four digits are 3025 or 2025

The scale is 1:600000. On the map, the distance between the two places is 10cm. The two trains leave from the two places at the same time and meet at 3:00
It is known that the speed of car a is two ninths faster than that of car B. how many kilometers per hour is the speed of car B

Actual distance: 10 △ 1 / 600000 = 6000000 cm = 60km
Speed and speed: 60 △ 3 = 20 km
B speed: 20 (1 + 2 / 9 + 1)
=20÷20/9
=9 km