Speed of motorcycle Li Fei bought a second-hand motorcycle. The next day, when he started, he saw that the number on the odometer was a symmetrical number 15751. After riding for 4 hours, a new symmetrical number appeared on the odometer. Can you tell the average speed of his motorcycle? As it was his first time riding, his speed did not exceed 100 km / h

15751 + 4x = a (symmetric number)
A

The curve equation is 16 parts x square + 9 parts y square = 1, and the tangent equation (3,2 parts 3 under 2 × root sign) is solved

Obviously, the tangent slope over (2 √ 3, 3 / 2) exists. If K is set, then the tangent is Y - (3 / 2) = K (x - 2 √ 3)
Substituting into the elliptic equation, the quadratic equation of one variable with respect to X or Y is obtained. ∵has only one intersection point, so the discriminant △ = 0 and two K values are solved
But it is noticed that (2 √ 3, 3 / 2) is in the first quadrant, so there should be K

The two teams transport a batch of goods at the same time. Party A transports 1 / 20 of this batch of goods per hour separately. When the transportation is finished, the number of tons transported by Party A is 3 / 2 of that of Party B, and Party A transports this batch together

At the same time, a was 1.5 times as much as B,
So if Party B transports 1 ton, Party A transports 1.5 tons
1.5 / (1.5 + 1) = 3 / 5 = 60%

When m is a positive integer, the solution of the equation X-2 / x-m = 2 / 3-x about X is nonnegative

From the problem (x-m) / (X-2) = (2-x) / 3, we know that 3 (x-m) = (X-2) multiplied by (2-x) to simplify the square of x-x-m + 4 = 0. From the problem (1), the square of b-4ac greater than or equal to 0 (2), the sum of two solutions - (B / a) = 1 > 0 (3), the product of two solutions C / a = 1 / (4-m) greater than or equal to 0 (4) m does not equal to 4-m > of 4-solution inequality

There is a pile of yellow sand on a construction site. It takes 2.5% 4 tons in the first day, and 8% 5 tons less in the second day than in the first day. If the remaining yellow sand is 5% more than the sum of the previous two days, how many tons of yellow sand are left

1 / 5 + 14 / 5 + 14 / 5-5 / 8 = 207 / 40 (ton)

If the line L and the line x + Y-1 = 0 are symmetric about the Y axis, we can find the equation of the line L and design an algorithm to solve the problem

∵ the slope of the line x + Y-1 = 0 is - 1, and it intersects at (0,1) point on the Y axis,
And ∵ the line L and the line x + Y-1 = 0 are symmetric about the Y axis
The slope of the line L is 1 and it passes through (0,1),
Then the equation of line L is y = x + 1, that is, X-Y + 1 = 0
So the answer is: X-Y + 1 = 0

There are 64 people in the first workshop and 56 people in the second workshop of a factory. Now, due to work needs, the number of people in the first workshop is half of that in the second workshop. How many people need to be transferred from the first workshop to the second workshop?

Suppose you need to transfer x people from the first workshop to the second workshop, according to the meaning of the question: 2 (64-x) = 56 + X, the solution is x = 24; answer: you need to transfer 24 people from the first workshop to the second workshop

If x / 2 = Y / 3 = Z / 4, then the value of X & # 178; - 2Y & # 178; + 3Z & # 178; / XY + 2yz + 3xz is the process

From X / 2 = Y / 3 = Z / 4, y = 3x / 2, z = 2x
x²-2y²+3z²/xy+2yz+3xz=17x²+8

There are 54 students in class 6 (1), of which the number of boys is 45% of that of girls. How many boys are there?

4 + 5 = 954 × 49 = 24 A: there are 24 boys

If x = 1y = 2 and x = 2Y = 3 are about the XY equation
Given that x = 1y = - 1 and x = 2Y = 3 are two solutions of the equation y = KX + B about X. y, then the equation is

Substituting x = 1, y = - 1 into the equation y = KX + B, we can get: K + B = - 1; substituting x = 2, y = 3 into the equation y = KX + B, we can get: 2K + B = 3
Synthesis K + B = - 1,2k + B = 3
It can be solved that k = 4, B = - 5
Therefore, the original equation is y = 4x-5