If the corresponding points of two rational numbers on the number axis are on the same side of the origin, then the product of the two rational numbers will be () numbers, and the positive and negative characters will be filled in the brackets

If the corresponding points of two rational numbers on the number axis are on the same side of the origin, then the product of the two rational numbers will be () numbers, and the positive and negative characters will be filled in the brackets

If the corresponding points of two rational numbers on the number axis are on the same side of the origin, then the product of the two rational numbers is (positive), and the positive and negative properties are filled in the brackets

Given that 1x − 1y = 3, then the value of the algebraic expression 2x − 14xy − 2yx − 2XY − y is______ ．

Solution 1: ∵ 1x-1y = - x − YXY = 3, that is, X-Y = - 3xy, then the original formula = 2 (x − y) − 14xy (x − y) − 2XY = - 20XY − 5xy = 4. Solution 2: divide the numerator and denominator of the original formula by XY at the same time, 2x − 14xy − 2yx − 2XY − y = 21y − 14 − 21x1y − 2 − 1x = 2 × (− 3) − 14 − 3 − 2 = 4, so the answer is: 4

This is a judgment question

This problem is right. Objects must be made up of matter. Matter must have weight and volume, but some matter is too small, like no volume

(an + BN) (?) = square of a - 2n power of B (an + BN) * (?) = (a ^ 2) - (b ^ 2n)

(a+b^n)*(a-b^n)=a^2 - b^2n
(a^n+b^n)*(a^n-b^n)=a^2n - b^2n

Ask a math problem: if the remainder of 34 and 56 divided by M is the same, and M is an odd prime number, how much is the remainder of M divided by 72

If the remainder of 34 and 56 divided by M is the same
The result of 56-34 = 22 divided by m should have no remainder
That's M = 11
72 divided by 11 leaves 6

27 8 / 15 △ 7 simple operation

=（28-7/15）/7
=28/7-(7/15)/7
=4-1/15
=3 and 14 / 15

General solution of differential equation y "- y '- 6y = 0

y"-y'-6y=0
The characteristic equation is as follows
r²-r-6=0
(r+2)(r-3)=0
R = - 2, or r = 3
therefore
The general explanation is as follows:
y=c1e^(-2x)+c2e^(3x)

How much is two liters of water

1 liter of water = 1kg = 2 kg, 2 liter = 4 liter = 4000 ml, so two liters of water is 4 kg
Drink water on the graduated measuring cup. The unit of scale is 1 ml. 1 liter of ML = 1000 ml

47.7 △ 0.11, vertical calculation

Determinant A0 1 1；1 a1 0…… 0；1 0 a2 …… 0；：：：：；1 0 0…… an

This is the "arrow" determinant, there should be A1, A2,..., an is not equal to 0
Add column 2 by - 1 / A1 to column 1
Add column 3 by - 1 / A2 to column 1
.
Add column n + 1 by - 1 / an to column 1
Transformation of determinant into upper triangular determinant
D = a1a2...an(a0-1/a2-1/a2-...-1/an)