If the slopes of lines L1 and L2 are equal, then L1 is parallel to L2 The answer is right, but if it coincides, it will not be parallel?

If the slopes of lines L1 and L2 are equal, then L1 is parallel to L2 The answer is right, but if it coincides, it will not be parallel?

The reference answer is wrong!
If the slopes of the lines L1: y = K1 * x + B1 and L2: y = K2 * x + B2 are K1 = K2
Then when B1 = B2, the two lines coincide (at this time, L1 parallel to L2 does not hold)

This is a tree

these are trees.

The vertex of the parabola y = x2 + MX + 1 is on the graph of the first-order function y = - 2x + 1

The key to this problem is to find M
Use vertex formula to express parabola, use m to express vertex coordinates. Vertex on the graph of a function, the horizontal and vertical coordinates of a fixed point satisfy the relationship of y = - 2x + 1. Take it in and solve M. don't forget to discuss the case of M = 0. Although it doesn't hold, explain that you have considered this case

The remainder of polynomial x243 + x81 + x27 + x9 + X3 + X divided by X-1 is______ ．

Let f (x) = x243 + x81 + x27 + x9 + X3 + x = q (x) (x-1) + R, then f (1) = q (1) × 0 + r = R, that is, r = f (1) = 1243 + 181 + 127 + 19 + 13 + 1 = 6

The parabolic equation with the center of hyperbola x216 − Y29 = 1 as the vertex and the left focus as the focus is______ ．

∵ the center of hyperbola x216 − Y29 = 1 is (0,0), the left focus is f (- 5,0), the vertex of the parabolic is (0,0), the focus coordinate is f (- 5,0), let the parabolic equation be y2 = - 2PY, P > 0, then P2 = 5, the solution is p = 10, and the parabolic equation is y2 = - 20x

Chapter 15 a topic of integral multiplication and division and factorization: (x-2y-z) ^ 2

(x-2y-z)^2=x^2+4y^2+z^2-2xy-xz+2yz

We know that a, B and C are real numbers, and for any real number x, there is always | x + a | + | 2x + B | = | 3x + C |, then a: B: C=

For any real number x, there is always | x + a | + | 2x + B | = | 3x + C |,
So let x = - C / 3
|-c/3+a|+|-2c/3+b|=0
Then: - C / 3 + a = 0, - 2C / 3 + B = 0
That is: C = 3A, C = 3B / 2
So:
a：b：c=1：2：3

The length of the line segment cut by the parabola on the x-axis is 2 units, and the maximum value is 3 when x = - 1. The analytical formula of the parabola is obtained

A:
When x = - 1, there is a maximum of 3
Then the vertex is (- 1,3)
Let the parabola be y = a (x + 1) ² + 3
Let y = 0 have:
a(x+1)²+3=0
(x+1)²=-3/a
So:
x+1=±√(-3/a)
Because: x1-x2 = 2 √ (- 3 / a) = 2
So: - 3 / a = 1
The solution is a = - 3
So: the parabola is y = - 3 (x + 1) &# + 3
So: y = - 3x & # 178; - 6x

It is known that one of the intersection coordinates of the parabola y = 2x2 and the straight line y = 3x + B is (3, m)

Substituting (3, m) into y = 2x2, M = 2 × 32 = 18, so the intersection coordinate is (3, 18), substituting the straight line y = 3x + B, 3 × 3 + B = 18, the solution is b = 9, so the analytic formula of the straight line is y = 3x + 9, simultaneous y = 2x2y = 3x + 9, the solution is X1 = 3Y1 = 18, X2 = − 32y2 = 92. So the other intersection mark is (- 32, 92)

The route from a city to B city is 1200 km long. It takes 2 hours and 30 minutes for an aircraft to fly from a City downwind to B city, and 3 hours and 20 minutes for an aircraft to fly from B city upwind to a city. The speed and wind speed of the aircraft in windless flight are calculated

Let the speed of the plane flying without wind be x km / h, and the speed of the wind be y km / h. from the meaning of the question, we get 52 (x + y) = 1200103 (x − y) = 1200, and the solution is x = 420y = 60. Answer: the speed of the plane is 420 km / h, and the wind speed is 60 km / h