Simple calculation of 1105 / 18 * 72 = 4 420

Simple calculation of 1105 / 18 * 72 = 4 420

1105/18*72
=1105*（72/18）
=1105*4
= 4 420

If the polynomial - 2x & # 178; + ax + BX & # 178; - 6x + 1 is independent of X, then a =, B=

The answer is a = 6, B = 2

I don't know whether it's ternary or binary
In order to test the length of a train and the speed of the train when crossing the bridge, Xiao Gang observed that it took one minute for the train to go on the bridge from the beginning to completely crossing the bridge. The time for the whole train to be completely on the bridge was 40 seconds. The total length of the bridge was known to be 1000 meters. The length of the train and the speed when crossing the bridge were calculated
It's not a linear equation of one variable, it's a quadratic equation of two variables

Let the length of the train be x and the speed be y
(x + 1000) / y = 60 * 1 [1 minute = 60 seconds]
(1000-x)/y=40
Namely:
1000+x=60y
1000-x=40y
Two formula add: 2000 = 100y, y = 20
x=60y-1000=60*20-1000=200
A: the train is 200 meters long and 20 meters per second

Factorization of N times plus 1 or minus 1 of X
x^n+1=
x^n-1=
How to decompose these two formulas into (x + 1) * (?) or (x-1) * (?)

x^n+1=(x+1)[x^(n-1)-x^(n-2)+.+1]
PS: n is odd
If PS: n is even, it cannot be decomposed
x^n-1=(x-1)[x^(n-1)+x^(n-2)+.+x+1]
PS: n is any integer

[(0.8 + 1 / 5) × 24 + 6.6] / / 9 / 14-7.6=

[(0.8 + 1 / 5) × 24 + 6.6] / / 9 / 14-7.6
=(24+6.6)×14/9－7.6
=(27+3.6)×14/9-7.6
=42+5.6-7.6
=42-2
=40
This is my conclusion after meditation,
If I can help you, I hope you will give me a satisfactory answer
If not, please ask, I will try my best to help you solve it~
The answer is not easy. If you are not satisfied, please understand~

One piece is 3.5m long. If you saw it into two sections, the surface area just increased by 2.2 square DM. What's the volume of this piece of wood?

1129906419,
The bottom area is:
2.2 △ 2 = 1.1 (square decimeter)
The timber length is:
3.5 m = 35 decimeters
Volume of wood:
1 × 35 = 38.5 (cubic decimeter)

A number, first expand the number three times, add 6, and then divide by 3 minus 2 to be the first number. Why?

The reason is that 6 * 3 = 2-2 = 0, which means that the original number has not changed at all

The height of ABC under the mine is - 32.4 M. - 139.8 M. - 91.3 M. how many meters is point a higher than point B? How many meters is point C higher than point B
How much higher is a than C?

Point a is 139.8-32.4 meters higher than point B = 107.4m
Point C is 139.8-91.3 higher than point B = 48.5m
Point a is 91.3-32.4 meters higher than point C = 58.9 meters

Simple calculation: 23.5 times 5.66 minus 23.4 times 5.67 1.2 / (1.2 / 2.3) / (2.3 / 3.4) / (3.4 / 4.5)
Thank you! Come on, come on, come on, come on!

23.5×5.66-23.4×5.67
=(23.4+0.1)×5.66-23.4×5.67
=23.4×5.66+0.1×5.66-23.4×5.67
=0.1×5.66-23.4×(5.67-5.66)
=0.566-23.4×0.01
=0.566-0.234
=0.332
1.2/(1.2/2.3)/(2.3/3.4)/(3.4/4.5)
=1.2×(2.3/1.2)×(3.4/2.3)×(4.5/3.4)
=4.5

-2A ^ 2 * (1 / 2Ab + B ^ 2) - 5A * (a ^ 2b-ab ^ 2), where a = 1, B = 2

-2a^2*(1/2ab+b^2)-5a*(a^2b-ab^2)
=-a³b-2a²b²-5a³b+5a²b²
=-6a³b+3a²b²
=-12+12
=0