After school, the students come out of the classroom in succession

After school, the students come out of the classroom in succession

After school, the students came out of the classroom one after another

There is no one in the classroom, only he is still studying hard

The classroom is quiet, only he is still studying hard

There is no one in the classroom, only he is still studying hard

The classroom is quiet, only he is still studying hard!

The third power of (a minus b) minus (a minus b)

=（a-b）【（a-b）²-1】
=（a-b）（a-b+1）（a-b-1）

It took 24 seconds for a train to pass through a 360 meter long tunnel and 16 seconds to find the length and speed of the train

Let the length of the train be x (m) and the speed be V (M / s)
360-x=24v（1）
216-x=16v（2）
If the two forms are combined, the result is as follows:
v=18m/s
x=72m

It is known that, as shown in the figure, ABCD is a square, ∠ fad = ∠ FAE

Extend CB to g, so that BG = DF, connect AG, ∵ quadrilateral ABCD is square, ∵ AB = ad, ab ∥ CD, ∥ d = ∥ ABC = 90 °, ∥ 5 = ∥ BAF = ∥ 1 + ∥ 3, ∥ ABG = 180 ° - ∥ ABC = 90 ° in △ ABG and △ ADG, ab = ad ≌ ABG = ADF = 90 ° BG = DF, ≌ ABG ≌ ADG (SAS)

How many light years does it take for the earth to reach the sun?
There should be scientific basis, don't talk nonsense
How much light per second from the earth to the sun?

We set the distance between the earth and the sun as 1 light-year, the speed of light propagation in vacuum is about 300000 kilometers per second, and the distance between the sun and the earth is about 150 million kilometers Reference to high school geography textbooks

In a certain area, the telephone charge is 0.2 yuan three minutes before charging, and 0.1 yuan for every more than one minute after three minutes. Granny Xiaohong made a phone call, which cost 1.7 yuan in total
How many minutes did she play?

3 x 0.2 = 0.6 (yuan)
1.7-0.6 = 1.1 yuan
1.1 △ 1 = 1.1 (min)
1.1 + 3 = 4.1 (min)

The rectangle ABCD is folded along the straight line Mn so that point d falls at B. points E and F are the intersection points of edges AD and BC at Mn, q is the intersection point of Mn at diagonal BD, P is any point on diagonal BD, pH is perpendicular to be at h, PG is perpendicular to ad at G?

EF bisects the diagonal BD vertically, so BD also bisects the diagonal EF vertically. Be = BF, that is, BD is the angular bisector of ∠ EBF. The distance from point P to be is pH = the distance from point P to BF. The sum of the distance from point P to AD and the distance to BF is the width of the rectangle, so AB = Ph + PG

The process of solving equation 5 (x-1) square-2 (x + 3) square = 3 (x + 2) square-7 (6x-1)

5(x-1)^2-2(x+3)^2=3(x+2)^2-7(6x-1)
5(x^2-2x+1)-2(x^2+6x+9)=3(x^2+4x+4)-7(6x-1)
(5x^2-10x+5)-(2x^2+12x+18)=(3x^2+12x+12)-(42x-7)
5x^2-10x+5-2x^2-12x-18=3x^2+12x+12-42x+7
3x^2-22x-13=3x^2-30x+19
3x^2-22x-13-3x^2+30x-19=0
-22x-13+30x-19=0
8x-32=0
x=4