(a-b)³×（a-b）²=?(x-y)×（y-x)³=?

(a-b)³×（a-b）²=?(x-y)×（y-x)³=?

(a-b)³×（a-b）²
=(a-b)^5
(x-y)×（y-x)³
=(x-y)×(-(x-y)³)
=-(x-y)^4

a²(x-y)³+4b²(y-x)³

a²(x-y)³+4b²(y-x)³
=a²(x-y)³-4b²(X-Y)³
=(x-y)³（a²-4b²）
=(x-y)³（a+2b）（a-2b)

Y = (A & # 178; - 1) x & # 179; + (a + 1) x & # 178; + X + (A-1) is a quadratic function

It's a quadratic function
a²-1＝0
（a+1）(a-1)=0
A = - 1 or a = 1
Because a + 1 ≠ 0
a≠-1
So a = 1

What is the first thing to determine when classifying rational numbers?

To classify rational numbers, the first thing is to determine the sign

Two trains a and B leave at the same time from a and B with a distance of 500 km. After 2.4 hours, the ratio of the distance they have traveled to the rest is 3:2
How long do we meet?

The speed is fixed, the distance ratio is equal to the time ratio
Therefore, it takes 2.4 △ 3 × 2 = 1.6 hours to complete the rest of the journey
A: they meet in another 1.6 hours

Given that the average of a group of data 1, 2, 0, - 1, x, 1 is 1, then the range of this group of data is 1______ ．

1 + 2 + 0-1 + X + 1 = 1 × 6, so x = 3, then the range of this group of data = 3 - (- 1) = 4

The distance between a and B is 140 km. It takes 4.5 hours for a car to go from a to B, and it takes an extra hour to return. How about the average speed of this car?

140×2÷（4.5+1+4.5）
=280÷10
=28 (km / h)
The average speed of the car is 28 kilometers per hour

From 1 to 1999, how many complete square numbers are there?
Urgent need

44 = 1936 45 = 2025 there are 44 perfect square numbers from 1 to 1999

The distance between the two places is 96 kilometers. A and B run from the two places at the same time and meet each other in 45 hours?

96 △ 45-54, = 120-54, = 66 km; a: car B travels 66 km per hour

As shown in the figure: in ladder ABCD, ad ‖ BC, ∠ B + ∠ C = 90 °, e and F are the midpoint of AD and BC respectively. Please explain the reason for EF = 12 (BC-AD)

It is proved that when the parallel lines of AB and CD cross point E and BC at g and h respectively, we can get ∠ EGH = ∠ B, ∠ EHG = ∠ C, ∵ B + ∠ C = 90 degree, ∵ EGH + ∠ EHG = 90 degree, ∵ GEH = 90 degree, ∵ EGH is a right triangle, ∵ AE ‖ BG, eg ‖ AB, ed ‖ HC, eh ‖ DC, ∵ quadrilateral abge and quadrilateral CD