5 / 4 * (- 0.6) / (- 3's Square) + 2 / 3 * (- 4 / 5) =?

5 / 4 * (- 0.6) / (- 3's Square) + 2 / 3 * (- 4 / 5) =?

5/4*(-0.6)/(-3^2)+2/3*(-4/5)
= 5/4*(3/5)/9 - 2/3 * 4/5
= 1/12 - 8/15
= - 27/60

Square of 2 + square of 4 + square of 6. + (2n-2) square

Using 1 & sup2; + 2 & sup2; + +n²=n(n+1)(2n+1)/6=4*1²+4*2²+…… +4(n-1)²=4/[1²+2²+…… +(n-1)²]=4(n-1)(n-1+1)[2(n-1)+1]/6=2n(n-1)(2n-1)/3

2 square + 4 square + 6 square + all the way up to 50 square

=4 * (1 square plus 25 square) = 4 * 25 * (25 + 1) (2 * 25 + 1) / 6, the result is calculated by yourself

How much is 11 square plus 12 square plus 13 square plus... Plus 19 square? Please write down the solution

How much is the square

Two plus minus four plus six plus minus eight... Plus forty-six plus minus forty-eight plus fifty

2-4 + 6-8 + 1o = 6, so there are five groups in 50, and the combination is 30. If you push the base to dozens, there are several groups left with six!

Find 847 to the 29th power of the number of digits

It should be 7! The number of 847 is 7, the number of the second power of 7 is 9, the third power is 3, the fourth power is 1, the fifth power is 7, and so on. The number of the 29th power is 7

What is the single digit of 29 to the power of 2007? What is the single digit of 23 to the power of 2007?

1、
The odd power of 29 is 9,
If it is even, the single digit is 1,
So 29 ^ 2007 is 9
2、
When the power of 23 is 1, the single digit is 3,
The second power time is 9,
The single digit is 7 to the power of 3,
When the power is 4, the single digit is 1,
When the power is 5, the single digit is 3, and so on,
Then 2007 / 4 = 501 + 3,
So the single digit of 23 ^ 2007 is 7

The first grade inequality of one variable
In June, Xiaoli collected 91 stamps and Xiaoliang 53 stamps. Since July, Xiaoli has collected 10 stamps a month and Xiaoliang has collected 4 stamps a month. Then, at least a few months later, Xiaoli's stamps will be twice as many as Xiaoliang's

After month x, Xiaoli's stamps are twice as many as Xiaoliang's
91+10X≥2×（53+4X）
X≥7.5
So at least eight months later, Xiaoli's stamps are twice as many as Xiaoliang's

There are two problems in the inequality of one variable and one degree
(1) A wholesaler sells a kind of clothing, the purchase price is 60 yuan per piece, and the original plan is to sell it at 90 yuan per piece. In order to reduce inventory and recover funds, it is decided to carry out preferential promotion: Based on the original sales price, if customers buy 1-20 pieces, 10% discount will be given; if they buy 21-50 pieces, 20% discount will be given; if they buy 51-100 pieces, 10% discount will be given, If you buy more than 100 pieces, you can get a 25% discount. One day, the wholesaler handled the business twice and sold 105 pieces. How much did he earn at most? How much did he earn at least?
(2) The scoring rules of a young singer Grand Prix are as follows: the highest score given by each judge is as follows: the average score given by all judges is 9.72; the average score given by the rest judges is 9.76 without one lowest score; the average score given by the rest judges is 9.76 without one highest score, The average score given by the rest of the judges is 9.68. Question: what is the score given by the judge who gives the lowest score to this contestant? How many judges are there altogether?
Otherwise, no points
fast

Let y be the profit, x the sales quantity and K the discount
Y = (90k-60) x, where
When 1 ≤ x ≤ 20, k = 90%;
When 21 ≤ x ≤ 50, k = 80%;
When 51 ≤ x ≤ 100, k = 75%;
When x > 100, k = 70%;
A total of 105 pieces were sold in two times
105=101+4：y=(90*0.70-60)*101+(90*0.9-60)*4=￥387
Similarly, if 105 = 104 + 1: y = 333
Similarly, if 105 = 51 + 54: y = 787.5
Similarly: if 105 = 50 + 55: y = 1012.5
Similarly, if 105 = 5 + 100: y = 810
Similarly, if 105 = 20 + 85: y = 877.5
It can be seen that the maximum and minimum profits are 1012.5 and 333.5 respectively

The problem of one variable one degree inequality in the first grade mathematics of junior high school
In the system of equations {2x + y = 1-m, if the unknowns X and y satisfy x + y = 0, what is the value range of M?
{x+2y=2
2x+y=1-m
x+2y=2

Substituting x + y = 0 into the system of equations, we get
{x=1-m
{y=2
Then y = 2 is replaced by 2x + y = 1-m, and the result is as follows
2x= -m-1
SO 2 (1-m) = - M-1
m=3