The three elements of the number axis are______ 、______ 、______ ．

The three elements of the number axis are______ 、______ 、______ ．

Because the number axis is a straight line that defines the origin, positive direction and unit length. So the three elements of the number axis are: origin, unit length and positive direction. So the answer is: origin, unit length and positive direction

Are there three elements in the number axis

Origin
Positive direction
Index value

If a (- 2,2) B (- 3,1), then the line y = 2x-1 is an absolute value Pb + absolute value PA, and the minimum P point coordinate is

Find out the symmetric point C of point a with respect to the line y = 2x-1, make points c and B a straight line, and the intersection point with the point y = 2x-1 is point P

It is known that a straight line passing through point P intersects circle O with radius r at two points a and B PA.PB= Absolute value of (r-square-op-square)
Be in a hurry

The tangent t passing through the leading circle P is the tangent point
Cut line theorem PA * Pb = Pt ^ 2 (this theorem can be proved by triangle similarity,
In RT triangle pot. Pt ^ 2 = Po ^ 2-ot ^ 2 = Po ^ 2-r ^ 2
So PA * Pb = | R ^ 2-op ^ 2|
Here's the front cut line theorem

As shown in the figure, P is the point on line AB, and AP = 5 / 2Ab, M is the midpoint of AB, PM = 1cm, find the length of line ab

A——P——M————B
∵ m is the midpoint of ab
∴AM＝1/2AB
∵AP＝2/5AB
∴PM＝AM-AP＝1/2AB-2/5AB＝1/10AB
∵PM＝1
∴1/10AB＝1
∴AB＝10（cm）

There are two points on the line AB: m and N. point m divides AB into 2:3 and point n divides AB into 4:1. If Mn = 3cm, find the length of AM and Nb

You can draw line segments. From left to right, the points are a, m, N, B
Because am / MB = 2 / 3, so am = 2 / 3MB
AM/MN+NB=2/3,
Because an / Nb = 4 / 1,
It can be seen that Nb = 1 / 4An or an = 4AB
AM/3+(1/4AN）=2/3
4NB-3/3+NB=2/3
That is, Nb = 1.5
When am / Mn + Nb = 2 / 3, am = 3

M. N is a point on the line AB, and am: MB = 2:3, an: NB = 3:4, and Mn = 4cm, find the length of ab

Let am be 2xcm long, MB 3xcm long, an 3ycm long and Nb 4ycm long
From the question, 5x = 7Y, we get x = 7 / 5Y
Mn = an-am = 3y-2x = 3y-14 / 5Y = 4, 1 / 5Y = 4, y = 20
So the length of this line AB is 20 (3 + 4) = 140 (CM)

Given the position of a, B and C on the number axis, as shown in the figure, simplify: | a + B | - | c-b|
Number axis: -- a -- 0 -- B -- C

The position of a, B and C on the number axis is shown in the figure,
Then: a + B < 0, C-B > 0
∴|a+b|-|c-b|
=-(a+b)-(c-b)
=-a-b-c+b
=-a-c

The position of the three numbers a, B and C on the number axis is shown in the figure, which is to simplify | B + C | + | B + a | + | - C-A | - | - | - | - - C B 0A
The picture may be rotten --
c

-（b+c）+b+a-（c-a）=2a-2c

Given the position of a, B and C on the number axis, as shown in the figure, simplify | a | + | C-B | + | a-c | + | b-a|

From the number axis, we get b > C > 0, a < 0, | C-B < 0, a-c < 0, B-A > 0, | a | + | C-B | + | a-c | + | B-A |, = - A - (C-B) - (A-C) + B-A, = - a-c + B-A + C + B-A, = 2b-3a