Square of (1 / 2-3 + 5 / 6-7 / 12) * - 6

Square of (1 / 2-3 + 5 / 6-7 / 12) * - 6

(1/2-3+5/6-7/12)*(-6）^2
=36*(1/2-3+5/6-7/12)
=18-108+30-21
=-81

Square of 1 / 2 + 2 / + 3 / 4 + 4 / 5 + 5 / 6 + 6 / 7 + 1 / 2 * (1 / 2 + 2 / 3 + 3 / 4 + 4 / 5 + 5 / 6 + 6 / 7) - (1 + 1 / 2 + 2 / 3 + 3 / 4 + 4 / 5 + 5 / 6 + 6 / 7)
(square of 1 / 2 + 2 / + 3 / 4 + 4 / 5 + 5 / 6 + 6 / 7) + 1 / 2 * (1 / 2 + 2 / 3 + 3 / 4 + 4 / 5 + 5 / 6 + 6 / 7) - (1 + 1 / 2 + 2 / 3 + 3 / 4 + 4 / 5 + 5 / 6 + 6 / 7) * (3 / 2 + 4 / 3 + 5 / 4 + 6 / 5 + 7 / 6)
Please hurry!

1/2+2/3+3/4+4/5+5/6+6/7=(1-1/2)+(1-1/3)+(1-1/4)+(1-1/5)+(1-1/6)+(1-1/7)=6-1/2-1/3-1/4-1/5-1/6-1/7=6-(1/2+1/3+1/6)-(1/4+1/5+1/7)=6-1-83/140=5-83/140=617/1403/2+4/3+5/4+6/5+7/6=1+1/2+1+1/3+1+1/4+1+1/5+1...

Train a and train B leave 1070 kilometers apart at the same time. Train a travels 90 kilometers per hour. After five hours, they have to travel a total of 160 kilometers to meet each other. How many kilometers does train B travel per hour?

(1070-160) △ 5-90, = 910 △ 5-90, = 182-90, = 92 (km); a: car B travels 92 km per hour

If the average of a group of data a, B, C, D is 3 and its variance is 2, then the average of data 2A + 1,2b + 1,2c + 1,2d + 1 is; the variance is; the standard deviation is

Average = 2 * 3 + 1 = 7
Variance = 2 ^ 2 * 2 = 8
Standard deviation = root 8 = 2 root 2

A motorcycles, B bicycles to each other, a 25 km long road, 0.5 hours later meet, a's speed is three times the speed of B, less than 6 km, find B's speed
By solving the equation, is the result 14km / h?

Let B's speed be x km / h
(x+3x-6)*0.5=25
4x-6=50
4x=56
x=14
B's speed is 14 km per hour

How many squares are there in natural number 24-8881?

25=5X5
8836=94x94
94-5 + 1 = 90

Two cars a and B start from a and B at the same time and run in opposite directions. They meet 80 kilometers away from the midpoint of the two cities. The speed ratio of a and B is 5:3
Q: how many kilometers are there between a and B?

Because it starts at the same time, so the time is the same
When the time is the same, the speed ratio is equal to the distance ratio, that is, the distance ratio of a and B is 5:3
Suppose: the distance of vehicle a is 5x, and that of vehicle B is 3x
Because the two cars met 80 kilometers from the midpoint of the two cities
So car a travels 160 kilometers more than car B (you can see by drawing the distance map)
That is, 5x-3x = 160
We get x = 80
Whole journey = 5x + 3x = 8x = 8 × 80 = 640km

Known - 1 / 2

First reduced to the same denominator
A = [(1-A ~ 2] ~ 2} / (1-A ~ 2) = (1-2a ~ 2 + a ~ 4), B = (1-A ~ 4) / (1-A ~ 2), d = (1 + a) / (1-A ~ 2), C = (1-A) / (1-A ~ 2)
If you look at the numerator, the bigger the numerator is, you can see that D is greater than C
If A-B is positive, then a is greater than B, and A-B = 2A ~ 4-2a ~ 2 = 2A ~ 2 (a ~ 2-1), because
0

There are 94 tons of coal in pile a and 138 tons of coal in pile B. nine tons of coal are transported out of the two piles every day. How many days later, the remaining coal in pile B is three times that in pile a?

After X days, the remaining coal in pile B is three times of that in pile a, (94-9x) × 3 = 138-9x & nbsp; & nbsp; & nbsp; & nbsp; 282-27x = 138-9x & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; 18x = 144 & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp

mean value inequality
If x > 0, then the maximum value of the function y = 3-x - (4 / x) is?

y=3-x-（4/x）
=3-(x+4/x)
To maximize y
Then (x + 4 / x) is minimized
∵x＞0
∴4/x＞0
From the mean inequality
（x+4/x)≥2√（x*4/x）
（x+4/x)≥2*√4
（x+4/x)≥4
The minimum value of (x + 4 / x) is 4
The maximum value of Y is y = 3-4 = - 1