What's the difference between positive proportion and negative proportion? I didn't get it.

What's the difference between positive proportion and negative proportion? I didn't get it.

(1) Positive proportion: two related quantities, one of which changes, and the other changes with it. If the ratio (quotient) of the two numbers corresponding to the two quantities is fixed, the two quantities are called positive proportion quantities, and their relationship is called positive proportion relations

0.2 of X + 3-0.4x-1 = - 2.5 for x =?
1 / 2 [X-1] - 3 [2 / 3 x + 1 / 2] = - 3 / 3 x
If a * b = the square of a + 2Ab, if [- 2] * x = - 2 + X, then x=【

1.0.2 of X + 3-0.5 of 0.4x-1 = 5x-0.8x-1 = 4.2x-1 = - 2.5, x = - 1.5 / 4.2 = - 5 / 14
1 / 2 [X-1] - 3 [2 / 3 x + 1 / 2] = 0.5x-0.5-2x-1.5 = - 1.5x-2 = - X / 3, we can see that - 2 = 7x / 6, x = - 12 / 7
3. [- 2] * x = 4-4x = - 2 + X, x = 6 / 5

(- 2 power of - 2A) & # 179; B & # 178; / / 8 power of 2a, and - 3 power of B
（a³﹚²·a²
2 to the power of - 2 - (1.414-0.4) & 186; + (& 189;)
-The - 2 power of 2 - (- 2) - 1 power - & # 188; + (- 3) - 2 power
(2.5) to the power of 2001 · (- 2 / 5) to the power of 2002
The sixth power of (&# 8539;) &# 179; · 0.5 & # 179; · 2 and the fifth power of 2
The 999 power of (- 4) · (188;) is 1000 power

8 (the tenth power of a)
Octave of a
five-fourths
five-ninths
two-fifths
zero point five
-¼

On the alignment of ruler's scale mark
I found that the scale of a ruler has a width. When measuring an object, should we consider the width? When measuring, should we aim the middle of the scale at the edge of the object, or the left or right side of the scale?
You two are right. I thought at that time that alignment must be one! I'm actually measuring it.

According to personal habits, it's OK to use middle alignment, left alignment or right alignment, but both ends must use the same alignment. For example, you can't use left alignment at the beginning and right alignment at the other end, which will cause large errors

We need to find the value of PI, all the way to the hundredth decimal,

0545 0580685501 : 6700 9567302292 1913933918 5680344903 9820595510 0226353536 : 6750 1920419947 4553859381 0234395544 9597783779 0237421617 : 6800 2711172364 3435439478 2218185286 2408514006 660443325...

To solve the plane equation of known plane 8x + y + 2Z + 5 = 0, which is parallel to the three coordinate axis and has tetrahedron Volume 1,

It is known that the intersection of the plane and the three coordinate axes is (0,0, - 5 / 2) (0, - 5,0) (- 5 / 8,0,0). The ratio of the distance between the three intersection points and the origin is Z: Y: x = 4:8:1, which is also the ratio of the distance between the target plane and the three coordinate axes! The volume of the target tetrahedron is 1, and the product of the distance between the three points and the origin is 3

Let f (x) = 12-12x + 1 (1) prove that f (x) is an odd function; (2) prove that f (x) is an increasing function in (- ∞, + ∞); (3) find the range of F (x) on [1,2]

(1) The definition domain of function f (x) is r, ∵ f (x) = 12-12x + 1 = 2x + 1 − 22 (2x + 1) = 2x − 12 (2x + 1), then f (- x) = 2 − x − 12 (2 − x + 1) = - 2x − 12 (2x − 1) = - f (x), that is, function f (x) is odd function; (2) ∵ y = 2x + 1 is increasing function, ∵ y = - 12x + 1 is increasing function, f (x) = 12-12x + 1 is increasing function in (- ∞, + ∞); (3) ∵ f (x) = 12-12x + 1 in (- ∞, + ∞) ）The function f (x) is also an increasing function in [1,2], that is, f (1) ≤ f (x) ≤ f (2), that is, 16 ≤ f (x) ≤ 310, that is, the range of the function is [16310]

A △ B = 7, so a can be divided by B, wrong?
Why is this sentence wrong?

The premise of division is: every number in division is an integer, and there is no remainder
Here a and B may be decimals or other non integers, can only be a kind of division, can not be judged as integral division, so this sentence is wrong

The eccentricity of the ellipse is 4 / 5. The major axis is 10. The distance from a point m on the ellipse to the left quasilinear is 5 / 2. Find the distance from the point m to the right focus

Let the distance from m to the left quasilinear be D, e = D / MF1 = 4 / 5, the solution is MF1 = 25 / 8, MF1 + MF2 = 2A = 10, the solution is MF2 = 55 / 8, that is, the distance to the right focus

The product of two prime numbers is 34 and 19. What are the two prime numbers

The two prime numbers are 2 and 17